The Massachusetts Republican Party is requesting an ethics investigation into Rep. John Tierney’s personal finances in a continued effort to highlight his wife’s guilty plea for aiding and abetting the filing of false tax returns by her brother.

A letter sent to the Office of Congressional Ethics by Massachusetts GOP Chairwoman Jennifer Nassour alleges that Tierney did not properly report his wife’s involvement in managing a Bank of America account, which was used to funnel $7 million in revenue from an offshore betting operation run by her brother, Robert Eremian. Nassour also asserts in the letter that Tierney should have declared as income $46,500 in funds his wife received from her brother.

“We expect Congressman Tierney to come clean on his involvement in this matter,” Nassour said in a release. “His constituents deserve the truth about what he knew about his wife’s $7 million in illegal gambling revenue from an offshore operation.”

The letter suggests that Tierney should have abstained from voting in 2006 on legislation cracking down on Internet gambling. Tierney voted against the measure, which eventually became law, and Tierney’s opponent, Republican Bill Hudak, has suggested the Congressman was wrongly swayed in casting his vote.

“There are questions as to whether the Congressman acted ethically or in violation of other laws” in casting the 2006 vote, Nassour wrote in her letter.

Patrice Tierney pleaded guilty Oct. 6 to four counts of aiding and abetting the filing of false tax returns by her brother, who was also recently charged with racketeering and money laundering, among other charges. Both are awaiting sentencing.

Rep. Tierney spokeswoman Kathryn Prael dismissed the GOP’s ethics investigation request as an election year ploy.

“It’s no surprise that Republicans would file an ethics complaint against someone who hasn’t been accused of anything,” Prael said in a statement. “Congressman Tierney has not been involved in any investigation, no charges were ever made against him, and his financial disclosure forms are thorough, accurate, and in compliance. This is simply a political ploy launched days before Election Day.”

The Office of Congressional Ethics reviews possible violations and refers appropriate matters to the House Committee on Standards of Official Conduct, but the office cannot transmit findings to the committee within 60 days of an election.