J. Stephen Griles, the former deputy secretary of the Interior who has attracted intense scrutiny over his dealings with ex-GOP lobbyist Jack Abramoff, is set to testify before the Senate Indian Affairs Committee on Wednesday, according to a witness list for the hearing.

Griles, who left the Interior Department in January, was called by Indian Affairs Chairman John McCain (R-Ariz.) to appear before the committee to answer questions on the department’s actions on behalf of the Coushatta Tribe of Louisiana, an Abramoff client, in a casino dispute with another tribe, the Jena Choctaws. McCain is investigating allegations of fraud perpetrated by Abramoff and his business partner, Michael Scanlon, against a half-dozen Indian tribes that paid them more than $80 million in a three-year period.

Griles is the highest-ranking Bush administration official to become publicly enmeshed in the Abramoff scandal, and his scheduled appearance on Wednesday surprised those who have been following the case.

“This a big deal, a really big deal, if Griles testifies,” said a GOP source who has been interviewed by federal agents conducting their own Abramoff probe.

According to a memo circulated by the Indian Affairs Committee late Saturday night, “Documents in the Committee’s possession also raise a question of whether Mr. Abramoff had improper contact with senior Interior Department officials regarding tribal issues that were before the Department.”

Italia Federici, a GOP environmentalist who is close to Interior Secretary Gale Norton, is also expected to appear before the committee. Federici served as a conduit between Abramoff and Griles during the Coushatta-Choctaw dispute, according to media reports, and she was also an intermediary with the Interior Department when Abramoff sought help for a Michigan-based tribal client. Federici is president of the Council of Republicans for Environmental Advocacy; Abramoff had some of his tribal clients donate tens of thousands of dollars to CREA, including the Coushattas.

Griles is now a partner in the lobbying firm Lundquist, Nethercutt & Griles, and he represents such clients as the American Petroleum Institute, Newmont Mining Corp., Gold Fields Mining and the Quapaw Indian Tribe of Oklahoma. Former Rep. George Nethercutt (R-Wash.) is one of Griles’ partners.

According to The Washington Post, Abramoff used his ties to Griles in a bid to help fight off a casino request by the Jena Choctaws, a casino that would have threatened the Coushattas’ own highly lucrative gaming facility. Griles went as far as carrying a binder of materials prepared by Abramoff into a high-level department meeting on the Coushatta-Choctaw dispute. Abramoff also reportedly tried to hire Griles away from Interior in late 2003.

Griles did not return a call seeking comment for this article.

The inspector general at the Interior Department is still reviewing any contacts that Abramoff had with department officials, including Griles, according to Dan DuBray, Interior Department spokesman, and a Justice Department task force is looking into the matter as well. Abramoff was indicted in August in Florida on federal mail and wire fraud charges related to the purchase of a Miami-based casino cruise ship line.

Abramoff’s old firm, Greenberg Traurig, is also set to have a representative at Wednesday’s hearing.

Fred Baggett, who chairs the national government affairs practice with Greenberg, is slated to appear. Greenberg Traurig has shelled out millions of dollars in payments to some of Abramoff’s old tribal clients in an effort to head off legal action against the firm, although the Coushattas have sued Abramoff, Scanlon and Greenberg Traurig in state court for an undisclosed amount, although the pair raked in $32 million in fees from the tribe.

Jill Perry of Greenberg Traurig confirmed that Baggett would appear on Wednesday. Perry said this was the first time that anyone from the firm had been invited to testify before Indian Affairs. “We have been cooperating with all ongoing investigations [of Abramoff] and will continue to do so,” Perry said.

Kevin Sickey, chairman of the Coushattas and a former tribal policeman, will testify on Abramoff and Scanlon’s work for the tribe.

Also scheduled to appear is William Worfel, a formal tribal council member who served as the main tribal contact for Abramoff and Scanlon.

In addition, Chris Cathcart, a former associate at Scanlon’s Capitol Campaign Strategies, is on the witness list for Wednesday’s hearing. Abramoff and Scanlon used phony front groups, created with Coushatta money, to gin up public opposition to the Choctaws’ casino bid, and conservative activist and grass-roots strategist Ralph Reed was called in to assist their campaign as well.