HOUSTON -- The Federal Bureau of Investigation asked for the bank records of Houston City Councilwoman Carol Alvarado as it entered the investigation into improper bonuses at City Hall, KPRC Local 2 reported Thursday.

It's the first indication that the federal government is involved in the probe.

The FBI request is for all of Alvarado's bank accounts, open or closed. It went out Wednesday to major banks across the country through what's known as the loss avoidance alert system, which is an electronic network connecting banks with law enforcement.

The FBI would not comment on the investigation. But Harris County District Attorney Chuck Rosenthal confirmed for KPRC that the federal request was made.

Alvarado oversaw the mayor pro tem's office where four employees were recently fired.

The Office of Inspector General found Rosie Hernandez, Christopher Mays, Florence Watkins and Teresa Orta received unauthorized bonuses worth more than $140,000 in 2005.

Rosenthal said Alvarado is not the target of a criminal investigation.

Her attorney, Rusty Hardin, told KPRC that the FBI's involvement was expected because Alvarado is a public official.

Her spokesman, Joe Householder, said her account numbers have now been forwarded to the district attorney's office.

"So they can get a hold of it as quickly as they can," Householder said. "That actually happened this afternoon. We had reached out to them earlier and said, 'If you want this material, you can have it.' And, just as an extra step, we e-mailed those numbers to them."

Hardin said he contacted the FBI several weeks ago offering to make Alvarado's or any records available. He said he has not yet heard from the agency. Hardin said this is a natural progression in the investigation and not an indication that Alvarado has done anything wrong.

The Civil Service Commission will hold appeal hearings of the four fired employees on April 4.