Federal investigators are examining real estate transactions on Florida's Gulf Coast involving two Allegheny County judges and a former Monroeville high school tennis champion who is accused by one of the judges of forging documents.

Participants in at least some of the deals include Common Pleas Judge Robert P. Horgos, Senior Judge Gerard M. Bigley and the tennis player, Alfredo J. Sararo III, a one-time Allegheny County probation officer who relocated to Florida and became heavily involved in the booming real estate market.

While the exact nature of the investigation by FBI and Internal Revenue Service agents is not known, civil court documents detail a separate ongoing battle between Judge Horgos and Mr. Sararo over valuable real estate bought by the judge in Florida's bubble market between 2004 and 2006.

Attorneys for both judges have cast their clients as victims who were potentially duped and stand to lose substantial sums of money.

"Judge Horgos has been very badly treated and defrauded out of a great deal of his own personal money, conservatively $500,000 at least," said Louis M. Tarasi Jr., one of Judge Horgos' attorneys.

Judge Horgos, 59, of Sewickley Hills, deferred to his lawyers for comment.

Judge Bigley, 68, of Robinson, a former U.S. Treasury Department criminal investigator, also declined comment other than to say, "I'm not a target of any investigation."

Judge Bigley's attorney, H. Yale Gutnick, said: "I know of no federal investigation. I know of no contact [by federal authorities] that has been made with my client."

Margaret Philbin, spokeswoman for the U.S. attorney's office in Pittsburgh, declined comment.

Judge Horgos has filed three lawsuits in Florida this year alleging that Mr. Sararo forged his name on deeds to four properties -- one in Port Charlotte, Fla., and three in Cape Coral, Fla. -- effectively stripping them from the judge's ownership without his approval.

Robert Rosenblatt, a Miami lawyer representing Mr. Sararo, said only that his client denies the forgery allegations.

In a countersuit to the complaint brought by Judge Horgos, Mr. Sararo fired back, saying the judge has "breached multiple contracts" regarding real estate in Florida.

One document included in the counterclaim is a promissory note showing that Mr. Sararo loaned Judge Horgos $157,011 in November 2006. The note is typed on Judge Horgos' official court stationery.

Mr. Sararo claims that Judge Horgos has reneged on a promise to repay the loan.

In addition, Mr. Sararo says he provided $649 for Judge Horgos to make car payments in June and July 2007, and gave $4,610 to the judge to pay for a contractor to work on his luxury Naples condominium in July 2007.

Mr. Sararo claims Judge Horgos has repaid only $1,875 of the contractor loan.

Mr. Sararo also said in court papers that in December 2006 he agreed to pay Judge Horgos $2,400 for two jerseys autographed by Steelers quarterback Ben Roethlisberger. Judge Horgos delivered only one jersey and refused to turn over the second one or refund the money, Mr. Sararo said.

Judge Horgos' financial disclosure forms for 2006 and 2007 to the state Supreme Court mention several loans and some of his Florida real estate holdings. But there is no mention of any loans or gifts from Mr. Sararo.

Judge Bigley's disclosure statements for the same years make no mention of his Florida properties.

By order of the Supreme Court, judges annually are required to file statements of financial interests that include a listing of creditors, real estate interests and gifts they received.

Judge Bigley also had dealings with Mr. Sararo. Records show that the judge bought property from Mr. Sararo in Cape Coral in Lee County. The judge still owns the property, but Mr. Gutnick said "issues" arose over the deals and prompted Judge Bigley to hire an attorney.

"We're trying to find out exactly who encouraged [the judge] to make these investments, No. 1, who actually implemented the investments for him, No. 2, how much money was involved in the transactions, and whether or not the funds that Gerry invested were used properly," Mr. Gutnick said.

One of Mr. Sararo's co-defendants in two of the lawsuits is Eric Harrington, co-founder of Moniker Online Services in Pompano Beach, Fla., a company that registers Internet domain names. Judge Horgos alleges that three of his Florida properties were wrongfully deeded to Mr. Harrington by Mr. Sararo.

Mr. Harrington's lawyer, Jeffrey Fridkin of Naples, did not return a telephone message.

Mr. Gutnick allowed that the real estate deals have contributed to a rift between the judges, who are decades-long friends and colleagues.

On two occasions, Judge Bigley campaigned for Judge Horgos, seeking votes from his fellow judges to elect Judge Horgos to the position of president judge. Both bids failed.

Mr. Sararo, 38, of Naples, a former Gateway High School tennis star, won the WPIAL singles championship in 1988, later taught tennis at The Racquet Club in Monroeville and briefly played on the pro tour.

He also worked as a probation officer from September 1997 until March 1999. In that role he would have dealt with Common Pleas Court judges in some capacity, but it is not clear how his relationships developed with the two judges whose real estate dealings are under scrutiny.

Mr. Gutnick said Judge Bigley does not recall Mr. Sararo from his courthouse days. Mr. Sararo's name appears in records that show he sold property to Judge Bigley in 2004 and 2005 in Florida, although it is not clear how he and the judge came into contact for those deals.

Judge Horgos has known Mr. Sararo and his family for years, according to Mr. Tarasi.