BUFFALO, N.Y. -- Late Thursday morning investigators executed a search warrant at the Buffalo home of former Erie County Democratic Chairman Steve Pigeon.

"I'm not sure how the press was alerted to this but we hope it's not the Attorney General's office. That's normally not how they work in these government investigations." attorney Kevin Burke said.

Pigeon's attorneys said the FBI is assisting the State Attorney General's office with the investigation involving an inquiry into a political action committee called the WNY Progressive Caucus. They said they had offered full cooperation and were surprised by the search.

"They're going through my clients condo so we want to make sure we have an inventory of whatever they take or copy, make sure that they comply with whatever instrument they use to go through his condo and make sure my client's rights are protected," Burke said.

"I am very surprised. I'm surprised that the FBI's involved," Erie County Legislator Betty Jean Grant, D, said. 

Grant said she's not surprised there's an investigation involving the WNY Progressive Caucus of which Pigeon was a major donor. In August 2013 she filed complaints with the Erie County Board of Elections and the now-disbanded Moreland Commission.

"I never got an answer and then maybe October of last year, 2014, after the Moreland Commission was disbanded, I got a call from New York State Police for an interview," she said.

She discussed with investigators how she questioned the tactics of the PAC that appeared to be targeting candidates endorsed by the Erie County Democratic Committee, including her.

"They were asking about why I believed I had been unfairly targeted, why Mr. Pigeon would spend so much money trying to unseat me and they asked to see some of the literature which I had," Grant said.

But she believes after her interview and Thursday's events the investigation has grown. Investigators also searched the homes of former Buffalo Deputy Mayor Steve Casey and Chris Grant, the current Chief of Staff for Congressman Chris Collins.

"In my dealing with the WNY Progressive Caucus, Mr. Casey's name nor Mr. Grant's name never came up and I didn't see them contributing any money to that caucus either," she said.

Collins said in a short statement that Grant will continue to voluntarily cooperate with the investigation and that he expects a quick resolution.

Meanwhile current Erie County Democratic Chairman Jeremy Zellner declined to comment on the investigation.

"It is my hope that if any laws have been broken, that the individuals involved should be punished to the fullest extent of the law," he said in a statement.