Cook County prosecutors have demanded records from the county tax appeal board amid questions about property-tax breaks awarded to businessmen who are political supporters of a state lawmaker, the Tribune has learned.

The grand jury subpoenas to the Cook County Board of Review seek records on tax appeal cases that are already the subject of an internal board investigation involving state Rep. Paul Froehlich (D- Schaumburg) and a political associate who used to work for tax board Commissioner Joseph Berrios.

One of three elected board members, Berrios is also chairman of the Cook County Democratic Party and a Springfield lobbyist with close ties to House Speaker Michael Madigan, the state Democratic Party chairman.

Board members and their staffs have been investigating whether Froehlich used any "undue influence" through Victor Santana, the political associate who worked for Berrios, or anybody else to get the tax breaks for businesses in Froehlich's district, Commissioner Larry Rogers Jr. said. Rogers said he was aware that investigators for State's Atty. Anita Alvarez were looking at tax cases as well but wouldn't say whether they were the same ones.

The April and May subpoenas obtained by the Tribune sought the files for 25 tax cases, including several in which Froehlich helped suburban business owners who got tax breaks. That included two hotel operators who together donated more than $36,000 to his campaign, according to state records.

Froehlich said in a statement to the Tribune that he has done nothing wrong and has yet to hear any allegation or evidence the businesses he helped didn't deserve the tax breaks. He said he used his experience as a former township assessor to offer advice for filling out forms and explain the tax appeal process.

"I have never asked for any fee or campaign contribution in return for my assistance and I never will," Froehlich said in the statement. He declined to be interviewed.

Berrios did not return calls for comment. The state's attorney's office did not return calls for comment.

Froehlich was at the center of a political controversy in 2007 when he upset Republicans by switching parties as the northwest suburbs became more Democratic. He won re-election to the House with the help of more than $388,000 from Madigan and the Democratic Party.

In recent weeks, staff members for Berrios, Rogers and fellow Commissioner Brendan Houlihan have spoken freely in open meetings about the accusations, which first came to light on a conservative Internet blog and later in reports by television station WFLD-Ch. 32. Amid the controversy, Froehlich has announced that he is not seeking re-election.

In two cases, the owners of separate Schaumburg hotels received tax breaks totaling $137,000.

John Muldoon, attorney for Bimal and Kiran Doshi, who own Comfort Suites on Higgins Road, said his clients discussed their property-tax increase with Froehlich at one of his fundraisers. The owners have given more than $18,000 to Froehlich.

"They've attended a few fundraisers and donated cash and services ... and they discussed the fact that their taxes had gone up," he said. "They don't remember much of the conversation, and he gave them general information, which they pretty much knew anyway."

Muldoon said other area hotels got bigger tax breaks. "If there was a quid, there was no quo because they were treated worse than other hotels," he said.

County records show that the board decreased the Comfort Suites assessment by $473,355 or about 36 percent, which works out to roughly a $94,600 annual tax savings.

Sharad Dani, the owner of the Wingate Wyndham hotel on Remington Road, told the board he spoke to Froehlich about his taxes and that Froehlich recommended a lawyer to use, but that Froehlich didn't ask for any money. Dani's companies donated more than $17,000 to Froehlich's campaign last year.

The decrease in Wingate's assessment translated to a tax savings of about $43,100.

Board staffers have questioned Dani's attorney, who is new to the tax appeal business and is friends with Froehlich and Santana. A political operative who did work for Froehlich and who worked for Berrios at the board for 10 years, Santana was allowed to visit private areas of the board offices until commissioners recently banned him.

Santana denied wrongdoing and said he was in the offices because they were talking about business unrelated to tax appeals.

jchase@tribune.com