HARRISBURG -- Two more staffers from the House Democratic Research Office are among those subpoenaed to testify before a grand jury investigating bonuses given by legislative leaders last year.

Michelle Borlinghaus, who received one of the largest bonuses, and Linda Notarangelo, who received one of the smallest, are expected to testify this week in a probe of whether the lump-sum payments were veiled compensation for campaign work, which would be illegal.

Both work in the research office, which in August was the subject of a search warrant for boxes believed to contain evidence that campaign work was done on state property, with state equipment or on state time.

Now they are among at least 13 Democratic staffers called to testify so far.

Democrats last month attempted to block the testimony, but the state Supreme Court rejected their motion to quash the subpoenas of employees, including seven named in court documents.

Names of six others newly subpoenaed came to light in Sunday's Philadelphia Inquirer.

Grand juries meet secretly to determine whether there is probable cause for the attorney general to file criminal charges. Names of those providing testimony are confidential, but the Inquirer said it obtained them from a source close to the probe.

Four of the six -- Ms. Borlinghaus, Ms. Notarangelo, Eric Webb and Karen Steiner -- received bonuses.

In all, House Democrats gave $1.9 million in staff bonuses last year, with most of the largest amounts going to those who were involved in campaigns. That's four times as much bonus money as the caucus spent in 2005, a non-election year.

The bonuses were given in secret, but came to light in news reports last winter, prompting state Attorney General Tom Corbett to investigate whether they were for campaign work.

Tom Andrews, spokesman for House Democratic Leader Bill DeWeese, did not return phone calls or e-mails yesterday.

He has previously said the bonuses were for legitimate legislative work and that employees who worked on campaigns used their days off, vacation time, accrued compensatory days or unpaid leaves of absence.

The attorney general's office won't say what it has learned so far in its investigation, but a Pittsburgh Post-Gazette review of campaign expenditures provides a glimpse into how much bonus recipients were involved in campaign work.

In 2006, Ms. Borlinghaus spent four months away from her state job as a research analyst to work full time for the House Democratic Campaign Committee and on Mr. DeWeese's re-election campaign. She received a bonus of $15,065, equal to 40 percent of her salary.

Campaign expenditure reports show that Ms. Borlinghaus traveled extensively in northeast Pennsylvania, where Rep. John Siptroth was waging a re-election campaign.

She was reimbursed from campaign coffers for driving at least 2,952 miles and for expenses including Red Bull energy drink, lip balm, disposable razors, two medical prescriptions and even a $15 co-pay for a doctor's appointment.

Ms. Borlinghaus could not be reached for comment yesterday.

Ms. Steiner, a research analyst who worked out of a different office in the Capitol, received a $15,065 bonus. Campaign records show she was extensively involved in a Harrisburg-based telephone bank funded by a committee to re-elect Mike Veon, former House whip who lost in the general election.

From March 28, 2006, to the May primary and from Sept. 18, 2006, to the November election she spent nearly every weeknight and several weekends there, according to pizza and doughnut receipts labeled "food for phone banks." She also traveled to Butler, Lawrence, Washington, Beaver and Lehigh counties on business for the House Democratic Campaign Committee, receipts show.

Ms. Steiner, whose base salary is $48,178, could not be reached for comment yesterday.

There is no evidence in campaign receipts that Mr. Webb, who received a $17,685 bonus, or Ms. Notarangelo, who received $445, were reimbursed for campaign work.

House Democratic employees are tight-lipped about the bonuses. Leaders who have spoken about them point to examples in other caucuses.

Mike Long, former chief of staff to ousted Senate President Pro Tem Robert Jubelirer, received a $22,500 bonus last year, even though he was occupied from Jan. 19 to May 16 with running his boss's unsuccessful primary campaign. The Republican State Committee paid him about $20,000 for that work.

He also received expense reimbursements from the campaign to re-elect Mr. Jubelirer and from the Common Sense Leadership Committee.

Overall, Senate Republicans gave $180,000 worth of bonuses to 16 employees last year, House Republicans gave $270,000 to 45 staffers and Senate Democrats gave $41,000 to 12.

The attorney general's office said Mr. Corbett, a Republican, is investigating all four caucuses.