A former District contracting officer who claims he was pressured to steer the city’s lucrative lottery contract to certain bidders preferred by some council members is cooperating with federal authorities, his attorney said Friday.

The U.S. attorney’s office, which has been conducting a wide-ranging public-corruption investigation in the District, has interviewed Eric W. Payne and this week subpoenaed documents related to the contract, said his attorney, Brian K. McDaniel.

It is unclear whether federal authorities are investigating the contract and whether the subpoena is connected to any of the other corruption probes. A spokesman for the U.S. attorney declined to comment.

The subpoena was disclosed Friday in U.S. District Court during a hearing in Payne’s wrongful-termination lawsuit against the city. Payne claims that he was fired after he refused to favor certain lottery contract bidders. McDaniel said the subpoena bolsters his client’s case. “It certainly puts our case into context,” he said.

But he did not disclose what Payne told investigators during the interview or what information was contained in the documents subpoenaed by the federal authorities. He would say only that the documents were related to the lottery contract and involved Mayor Vincent C. Gray, who was D.C. Council chairman at the time, and council member Jim Graham (D-Ward 1).

“I have had no contact with the FBI or the U.S. attorney’s office,” Graham said. “I have committed no wrongdoing in relation to the lottery contract. This is a self-serving statement by a plaintiff’s lawyer that has no basis in fact.”

A spokesman for the mayor did not immediately return a request for comment.

Payne wants to comply with the subpoena, McDaniel said. But some of the documents are under court protective order because of Payne’s suit. Magistrate Judge Deborah A. Robinson said authorities would have to file a request to lift the protective order on any documents. Last month, U.S. District Judge Richard W. Roberts ordered Gray and Graham to give depositions but narrowed the scope of questioning.

Manasi Venkatesh, an assistant general counsel for the D.C. Council, said during the hearing that she expected the deposition to be short because of the limited questioning. She also said the city planned to give Payne and his attorney correspondence pertaining to Payne’s termination.

One of the groups vying for the contract included Lorraine Green, who became chairman of Gray’s campaign, and Howard Brooks, a campaign aide who pleaded guilty last week to lying to federal investigators about payments he made to former mayoral candidate Sulaimon Brown to disparage Mayor Adrian Fenty on the campaign trail in 2010.

The contract is worth $38 million in sales over a five-year period. It was ultimately won by a partnership of Emmanuel Bailey, a local businessman, and Intralot.

Also last week, Tom Gore, assistant treasurer of Gray’s 2010 campaign, pleaded guilty to charges arising from the probe of Brown’s allegations that he was paid and promised a job to harass Fenty on the campaign trail. Last month, former council member Harry Thomas Jr. (D-Ward 5) was sentenced to 38 months in prison for stealing more than $350,000 funds meant for youth programs.