The state Fair Political Practices Commission is reviewing contributions that Assembly Member Tom Berryhill of Modesto gave to the Stanislaus County Republican Party to determine whether he illegally steered money to his brother's election bid.
FPPC executive director Roman Porter confirmed that the investigation is under way.
Laura Ortega, Berryhill's chief of staff, said he is complying with the review and has turned in documents to the FPPC.
California Watch, a Web-based investigative journalism outlet, put a spotlight on Berryhill's contributions to county Republican central committees in a piece The Modesto Bee published Jan. 3.
The story drew attention to a total of $25,000 Berryhill gave to the Stanislaus committee Oct. 27 and 29, 2008. The party delivered $40,000 through two donations Oct. 30 and 31 to a campaign fund for his brother, Bill Berryhill.
Tom Berryhill also gave $20,000 on Oct. 30 of that year to the San Joaquin County Republican Central Committee, which gave $21,000 to Bill Berryhill's campaign the next day.
Bill Berryhill went on to win a tight race against Democrat John Eisenhut to represent the 26th Assembly District, which covers parts of Stanislaus and San Joaquin counties.
Tom Berryhill's 25th Assembly District covers parts or all of Madera, Mariposa, Mono, Calaveras, Tuolumne and Stanislaus counties. He is running for a state Senate seat that includes Clovis and large parts of eastern Fresno County.
Jim DeMartini, chairman of the Stanislaus County Republican Central Committee, said Tom Berryhill didn't tell the group how to spend the money. DeMartini said he received a letter dated Dec. 14 from the FPPC alerting him to the investigation.