STAMFORD, Conn. – Attorneys seeking a new trial for Kennedy cousin Michael Skakel in the death of his neighbor say a man recently implicated in the 1975 killing has refused to answer questions, and they want a judge to compel him to testify, according to court documents.

Skakel, who was convicted of murder in 2002 and is serving 20 years to life in prison, sought a new trial after Gitano “Tony” Bryant, a cousin of basketball star Kobe Bryant, claimed that two of his friends killed 15-year-old Martha Moxley.

Skakel’s attorneys identified the two men in court papers as Adolf Hasbrouck of Bridgeport and Burt Tinsley of Portland, Ore.

In court documents, Skakel’s attorneys said Hasbrouck invoked his Fifth Amendment right against self-incrimination at a deposition last week. Among the questions asked were, “Did you kill Martha Moxley?” defense attorneys said.

Hope Seeley, one of Skakel’s attorneys, said Bryant’s claim was a significant development in the case.

“Once all of the facts of this case are fully examined, it will be demonstrated that the so-called ‘evidence’ that served as the basis for Michael Skakel’s conviction is seriously flawed and Michael Skakel deserves a new trial,” Seeley said.

Skakel’s attorneys filed a motion Wednesday to compel Hasbrouck to testify about matters that do not incriminate him and turn over phone records and other documents, including any e-mails he sent to Tinsley and others.

Neither man has returned repeated telephone calls from The Associated Press. Hasbrouck’s attorney, Lawrence Schoenbach, declined comment.

Tinsley’s deposition has not taken place yet.

Bryant’s allegation surfaced in 2003, a year after Skakel, a nephew of Ethel Kennedy, was convicted of bludgeoning Moxley with a golf club in their gated neighborhood in Greenwich when they were both 15.

The petition for a new trial is separate from an appeal Skakel lost before the Connecticut Supreme Court earlier this year that argued, among other issues, that the five-year statute of limitations had expired when he was charged in 2000. Skakel’s attorneys have said they will take that issue to the U.S. Supreme Court next month.

Prosecutors have said they are highly skeptical of the new claim.

“We will be more than happy to meet all their claims if and when this matter ever gets to trial,” said prosecutor Jonathan Benedict.