The Senate Indian Affairs Committee has approved issuing broad subpoenas to lobbyist Jack Abramoff and a former aide to House Majority Leader Tom DeLay (R-Texas) in connection with the more than $45 million in fees they charged tribal clients.

In what panel members later described as a unanimous decision, the committee on Wednesday gave the go-ahead for issuing subpoenas to Abramoff and Mike Scanlon as well as to some businesses and firms they have been associated with over the past few years.

Sen. Ben Nighthorse Campbell (R-Colo.), the committee’s chairman, said the subpoenas would start going out later this week or early next week, although he held out the possibility that the tribal clients themselves might not be subpoenaed — an issue that Campbell and ranking member Daniel Inouye (D-Hawaii) expect to work out over the next few days.

“We’re looking at individuals and corporations much more than tribes,” Campbell said. He confirmed that Abramoff and Scanlon are among those who would receive summonses.

“A lot of people have been subpoenaed,” Inouye said after the closed-door executive session in which they were issued. He put the number at “more than 10,” while Campbell said the figure could be “as many as 15.”

Wednesday’s developments are the latest twist in the three-month-old committee investigation initiated by Sen. John McCain (Ariz.), the panel’s No. 2 Republican and the heir apparent to the chairmanship next year.

Abramoff, who resigned earlier this year from the law and lobbying firm Greenberg Traurig, billed four different tribes about $15 million between 2001 and 2003 while at the same time referred them to Scanlon, the former DeLay aide who worked closely with Abramoff as a public relations and grassroots campaign expert. According to internal audits and press reports in The Washington Post and other media outlets, Scanlon appears to have raked in twice as much as Abramoff — more than $30 million, and possibly much more.

There is evidence that the FBI is looking into how some of the tribes spent their money. The Interior Department is doing its own investigation. Once McCain went public with his complaints and coaxed Campbell into launching the investigation, Greenberg Traurig ousted Abramoff, citing its own preliminary internal inquiry that turned up unspecified actions that violated firm policy.

The firm is close to completing its own internal probe, for which it hired outside counsel, and may seek further retribution against Abramoff.

The firm declined to comment about the committee’s actions Wednesday. Abramoff’s lawyer, Abbe Lowell, released a statement declining to comment on the specifics of the committee’s actions because of its decision to act in secrecy. “Because the committee apparently decided to act in closed session, we don’t know what it did or what, if any, subpoenas have been issued,” Lowell said.

A lawyer for Scanlon did not reply to a request for comment.

Inouye said he expects Abramoff and his old firm to try to beat back the subpoena. “I would anticipate that they will try to resist,” he said.

At particular issue with Abramoff will be the work he did for several tribes who apparently have attorney-client confidentiality privilege with Greenberg Traurig. A few of the tribes are in internal feuds, with warring camps divided by their stance on the Abramoff-Scanlon work. It’s unclear whether those tribes will ever fully waive their confidentiality.

One tribe, the Saginaw Chippewa of Michigan, is now officially being run by a tribal council that has waived all confidentiality claims, and it appears any and all documents related to that tribe are probably in the committee’s possession. Scanlon has said that he turned over all his Saginaw documents.

While Campbell, the only American Indian in the Senate, said the tribes have a level of sovereignty that allows them to run their own affairs, he added that longstanding trusts between them and the U.S. government give Congress the right to oversee their actions.

He suggested that Abramoff and Scanlon may have engaged in financial wrongdoing similar to how telemarketers take advantage of elderly customers — something that tribal sovereignty doesn’t protect Abramoff and Scanlon from.

“That does not give them the right to have two people take advantage of them,” he said.