HARRISBURG — Eight employees of the House Democratic Office of Legislative Research spent months away from their state jobs to campaign full-time last year and still received taxpayer-financed bonuses ranging from $5,000 to more than $15,000 apiece, according to a published report.

A Pittsburgh newspaper examined campaign expenditure records to trace the activities of legislative staffers who shared in bonuses that the House Democrats paid in 2006 — the year they reclaimed the majority after 12 years of minority status.

State Attorney General Tom Corbett's office has empaneled a grand jury to investigate whether bonuses by all four legislative caucuses were rewards for government work, as legislative leaders contend, or illegal payments for political work they did to advance their parties' candidates.

House Democrats gave out $1.9 million in bonuses last year, which is $700,000 more than the combined total for the other three caucuses.

Legislative staffers commonly use vacation days and other authorized time off to work on campaigns and sometimes are paid with campaign funds, but it is illegal for them to do political work while they are being paid by the state.

Investigators have said they are scrutinizing all of the nearly $4 million in bonuses paid to legislative staffers in 2005 and 2006.

But the focus appears to be on the House Democrats and its research office, whose ostensible mission is to provide services to legislators' constituents. Last month, state agents raided the office and seized some of its records, according to newspaper reports.