WASHINGTON -- The Interior Department's former No. 2 official denied yesterday that he gave preferential treatment to a lobbyist under investigation for his work on behalf of Indian tribes and their casino interests.

Steven Griles' assertion was challenged by a one-time colleague and by senators who cited e-mails by the lobbyist, Jack Abramoff.

To the Senate committee investigating Mr. Abramoff and his partner, Michael Scanlon, Mr. Griles said it was "outrageous" and "untrue" that they had special access to him, as they claim.

But Michael Rossetti, a former legal counselor to Interior Secretary Gail Norton, told senators that he had been "alarmed" when Mr. Griles "all of a sudden had an inexplicable desire to be involved" in meetings with Ms. Norton dealing with the effort by the Jena Band of Choctaw tribe to open a casino near the Texas-Louisiana border. "Repeatedly on at least half a dozen occasions, he insisted on being in on meetings" affecting the Jena Band, Mr. Rossetti said.

Mr. Griles resigned in December as the department's deputy secretary.

Mr. Abramoff and Mr. Scanlon were hired as lobbyists by the Louisiana Coushatta tribe to work against efforts by the rival Jena Band of Choctaws to open a casino that could compete with the Coushatta's gambling operation near Lake Charles, La.

The Senate Indian Affairs Committee is investigating Mr. Abramoff and Mr. Scanlon and the more than $80 million they were paid between 2001 and 2004 by six Indian tribes with casinos, including the Coushattas.

Mr. Abramoff has been indicted by a federal grand jury in Florida on charges of fraud and conspiracy stemming from his role in the 2000 purchase of a fleet of gambling boats.

Late yesterday, the Senate committee released hundreds of pages of documents and among them were e-mails written by Mr. Abramoff in the summer of 2002 suggesting that Rep. Tom DeLay, R-Texas, wanted contributions from Mr. Abramoff's tribal clients.