MARKFIELD, England -- As Europe wrestles with the dissatisfactions of its 20 million Muslims and the spread of radical Islam, greater scrutiny is falling on its Islamic groups.

The largest and most important of these is the Federation of Islamic Organizations in Europe, a lobbying group representing Muslims in 22 countries. Its leader, Ahmed al-Rawi, has advised national politicians and testified before the European Parliament. This year, he attended Pope John Paul II's funeral.

Mr. Rawi's federation also has little-noticed ties to radical groups aiming to establish fundamentalist Islam across the Continent. It has founded schools that each year allegedly train hundreds of young Muslims in Saudi-style fundamentalist ideology. Some of Mr. Rawi's closest aides have channeled millions of dollars from Saudi fundamentalists to groups across Europe.

In an interview, Mr. Rawi endorsed suicide bombings in Iraq and Israel, saying Muslims "have the right to defend themselves." He said he identifies closely with foreign Islamic groups that promote fundamentalism.

Mr. Rawi's prominence underscores Europe's challenge in dealing with its growing, and restive, Muslim minority, which has shot to the top of its agenda. The concern has been driven by events from the 2004 train bombings in Madrid to weeks of violent riots in France's Muslim slums this year.

The riots underscored Muslim complaints of being treated as outsiders, consigned to slums and hobbled by high unemployment and crime. Muslim ghettos across Europe have provided a steady stream of recruits to jihadist groups fighting the U.S. in Iraq.

Partly in response, European politicians have sought to reach out to Muslim groups claiming to represent their communities. But a look at the federation reveals the difficulty of that task. Many of Europe's Muslim groups have complicated ties, both formal and informal, that can make it tough to screen out more radical groups and ideologues.

Wednesday, German police banned an Islamic group, saying it encouraged young Muslims to join jihad. The group, the Multikulti House association, has at least informal ties to the Islamic Community of Germany, a key pillar in Mr. Rawi's federation.

Many of Europe's radical Muslims are heavily influenced by the Muslim Brotherhood, an organization based in Cairo. Founded in the 1920s, it espouses an Islamist ideology that has stirred political-reform movements in the Middle East but also has encouraged intolerance and terrorism.

As Europe has become Islam's new frontier, the Brotherhood has spread political Islam, which weds religion and politics into a potent force that clashes with pluralistic democracies. From its beachhead in Germany, the Brotherhood has gone on to influence the most important Islamic group in France and a key council setting Islamic ideology in Europe. These groups are part of Mr. Rawi's network and previously were profiled in The Wall Street Journal.

A genial 58-year-old with a self-deprecating sense of humor, Mr. Rawi didn't deny having a close connection to the Brotherhood. But he took issue with the Brotherhood's reputation in the West, saying he admires the organization for how it stands up to the authoritarianism that rules many countries in the Mideast. "We are interlinked with them with a common point of view," he said. "We have a good close relationship."

Mr. Rawi came to the United Kingdom in 1975 to study engineering and became active in Muslim politics. He helped start the federation in the late 1980s, uniting a half-dozen Muslim organizations in Europe. Today, it includes some of Europe's biggest groups, such as the Union of French Islamic Organizations and the Islamic Community of Germany.

Like the Muslim Brotherhood, the federation has set up a wide range of institutions linking politics, education, charity work and religion. "It is difficult to define what we are," Mr. Rawi said. "We are a social-religious institution."

The 1990s saw the establishment of several key groups in Mr. Rawi's network, such as the Institut Europeen de Sciences Humaines. Launched in 1992, it has campuses in Paris, the Burgundy region of France and in Wales and aims to teach Islam to future imams and activists. The group says it has graduated more than 100 imams and has more than 450 part-time students each year.

Federation officials also have helped channel money to Islamic groups in the Balkans. A key figure in this effort is Ibrahim el-Zayat, who as head of the Islamic Community of Germany, a founding group in the federation, is one of Europe's most prominent Muslims.

Mr. Zayat serves on the board of directors for both the federation and for the European Trust, a U.K.-registered charity that has served as the network's fund-raising arm. He also has run a youth group affiliated with the network, the Federation of European Muslim Youth Organizations.

In 2002, German federal police launched an investigation of Mr. Zayat. According to copies of a report reviewed by the Journal, he allegedly transferred more than $2 million on behalf of the World Assembly of Muslim Youth, a Saudi-run organization that propagates Wahhabist fundamentalism, which isn't part of the federation.

Some of that money, according to the report, was sent by Mr. Zayat and another federation official, Ayman Sayed Ahmed Aly, to an Albanian charity, Taibah. Taibah's Bosnia branch last year was designated a terrorist organization by the U.S. government. Its Albanian branch was raided last year by the government there.

"The constellation of accounts, money flows and persons indicate that the accounts in Germany of Ibrahim El-Zayat and Ayman Sayed Ahmed Aly were used for carrying out fundamentalist Islamic activities in Europe," the report said.

Neither man was charged after the probe. When the transfers took place, supporting or being a member in a foreign terrorist organization wasn't illegal in Germany.

In an interview, Mr. Zayat said he wasn't acting in a capacity related to the federation but in a separate role as the member of the board of trustees of the Saudis' World Assembly of Muslim Youth responsible for Western Europe. He said he is against fundamentalism and joined the assembly to prevent the spread of its fundamentalist thought.

From inside, Mr. Zayat said, he could ensure the group was ineffective. But he had some duties, including money transfers. "I am their representative here and transferred it," he said.

Mr. Rawi said his federation has nothing to do with the activities of Mr. Zayat or Mr. Aly. "It is hard to prevent our members from working for charitable organizations," Mr. Rawi said.

In recent years, Western nations have put money flows from Persian Gulf states under intense scrutiny. That has spurred the federation to seek financial independence. Mr. Rawi said the federation has an annual budget of GBP 900,000, or about $1.5 million, with roughly GBP 400,000 coming from member organizations and the rest from donations, much of it from anonymous donors in the Gulf.

The European Trust was created in 1996 to break the federation's dependency on Gulf donors. For years, the federation's Web site touted the charity as one of its "central organizations." Six of the charity's trustees are federation members. Mr. Rawi heads both the trust and the federation.

The trust has directly subsidized federation projects, such as its three colleges and the local Islamic centers that constitute the federation. Until recently, the federation's Web site said the trust "was established in order to support and promote our work by providing stable financial reserves." According to the trust's 2003 financial statements, the most recent available, most of its charitable giving went to students studying at the three Islamic teaching institutes.

Asked last year about the ties between the federation and charity, the U.K. Charity Commission said such a relationship could be a problem. Charities are not supposed to support lobbyists. The commission then asked the trust if it had relations with the federation. A short time later, the federation changed its Web site and erased all mention of the trust. The trust's Web site was shut down and recently reopened without any mention of the federation.

In a subsequent interview, Mr. Rawi said the trust, now renamed Europe Trust, "is fully independent now" of the federation. "It is a British charitable organization, but of course there are many like myself in the trust," he said.

Abdel Karim Bensiali, a professional charity manager who now is executive director of the trust, said in an interview that he will improve the trust and make it serve all of Europe and not simply the federation's projects. He added, though, that he doesn't have full control over the trust's finances because Messrs. Rawi and Zayat often take action without his knowledge.

For now, Mr. Rawi's federation remains the primary partner for governments seeking dialogue with Europe's Muslims. In part, it benefits from its organizational skills. Most Muslims arrived in Europe as laborers and have little interest or ability to interact with politicians. Mr. Rawi and the heads of federation groups are different: professional organizers, most with university degrees, able to speak on an equal footing with Europe's political elites.

That has made even controversial groups allied with Mr. Rawi focal points for government efforts to reach the Muslim population. For instance, the federation sublets its headquarters from the Islamic Foundation, a group allied to Jamaat-e-Islami, a Pakistani group dedicated to establishing a theocracy in that country. Islamic Foundation recently officials have joined in British "working groups" set up after last summer's London bombings to prevent extremism.

Ilana Conn, a spokeswoman for the Home Office in London, said the government doesn't intend to follow all the advice it solicits. "For us it was essential to reach a whole selection, a whole shade of opinions," Ms. Conn said. "And in those groups there would inevitably be people with views we would not necessarily agree to."

Mr. Rawi also has gone to several meetings of the Islamic-Catholic Liaison Committee. Vatican officials said the contacts don't mean they endorse the federation. "It's important to know their history and development in Europe," said Msgr. Khaled Akasheh, a Vatican official.

In Brussels, the federation is regularly invited to give testimony to committees of the European Parliament, as the only European-wide body representing Muslims. A key issue for it has been the headscarf, or hijab, which it views as every Muslim woman's duty to wear. The group helped set up a lobby organization known as Pro-Hijab and has organized pro-hijab demonstrations.

Baroness Sarah Ludford, a member of the European Parliament who invited the federation to a committee meeting, said she wasn't exactly sure who comprises the group. "This can be a tricky area to navigate," Baroness Ludford said. "We have to know who we're talking to."