Massachusetts rep's campaign shaken by claims about family's Antigua gambling ring

Shown here is Rep. John Tierney, D-Mass. (AP)

Republicans are stepping up pressure on Massachusetts Rep. John Tierney in the wake of fresh claims he knew about his in-laws' illegal offshore gambling ring and let his wife take the fall for it.

The claims against the eight-term Democratic congressman rekindled the gambling scandal as a campaign issue -- his wife's brothers are at the center of it and have faced charges for running the Antigua-based operation. The congressman's wife also was sentenced to 30 days in jail in January 2011, but so far Tierney has stayed above the allegations.

Last week, though, Tierney's brother-in-law Daniel Eremian reportedly called Tierney a "liar" and said he "knew everything" after Eremian was sentenced to three years in prison. The next day, another brother-in-law -- Robert Eremian, who is still living as a fugitive in Antigua -- told the Boston Globe the same thing.

"I will verify everything that my brother said, which will show John Tierney is lying," Eremian told the newspaper, in a phone interview from the island. He has been indicted on illegal gambling and money laundering charges for running Sports Off Shore there. He also alleged Tierney "threw my sister under the bus for his political career."

Tierney adamantly denies the charges. A spokeswoman for the congressman called the claims "bizarre, unsubstantiated and false."

Tierney, in an interview over the weekend with MyFoxBoston.com, questioned the brother-in-laws' credibility.

"They should consider the source, for sure, and compare it against my integrity, my honesty over the years," Tierney said. "I've been very straightforward ... so let's get on with the campaign."

Tierney personally responded to another claim from Daniel Eremian that the two of them "sat in the boxes with bookies at Fenway Park." Tierney told the Boston Herald that the comments came from somebody who's "distraught" and "bitter."

"There are 37,000 in Fenway, and I'm sure maybe one or two are bookies but they weren't with me," he told the Herald.

But the case is campaign fodder for Tierney's GOP opponent, Richard Tisei, and the National Republican Congressional Committee.

"The questions now are what did John Tierney know and when did he know it," NRCC spokesman Paul Lindsay told FoxNews.com. "The allegations beg him to come out and be more honest and open with his constituents about the troubling allegations that have been lodged against him."

Tisei, a former Senate GOP leader in Massachusetts, is a moderate-leaning Republican who's given Tierney a tough race for re-election. It's unclear where the race stands -- each camp has released internal polling in recent months claiming their side is ahead.

The NRCC has already bought up ad time for the Massachusetts 6th District race, and it's likely the scandal will play a starring role in those spots. The NRCC also has up a microsite dedicated to the story -- the site is called: "How Could Tierney Not Know?"

"The business was so close to Tierney that his wife was convicted and sentenced to jail time," the site says. "Yet for 15 years, and through two trips to the headquarters in Antigua, John Tierney claimed he knew absolutely nothing."

Tierney says he made two visits to Antigua and visited Robert Eremian but didn't know about the gambling operation.

Patrice Tierney served a 30-day jail sentence last year after pleading guilty to aiding and abetting the filing of false tax returns for Robert.

But she testified that she and her husband did not know that Robert was running an illegal gambling operation. She said she was managing a bank account to help him care for his children.

John Tierney has said his wife was betrayed by her brother, believing his income came from selling or licensing software to legal Internet gambling businesses.

FoxNews.com's Judson Berger and The Associated Press contributed to this report.