WASHINGTON —  A lobbyist under scrutiny for charging Indian tribes millions of dollars is now facing a call for a congressional investigation into his work for the government of the Northern Mariana Islands (search).

California Democratic Rep. George Miller on Thursday asked the House Resources Committee to examine Jack Abramoff's (search) activities while he represented the commonwealth, a tiny U.S. territory in the Pacific. The committee oversees U.S. territories.

Miller's request came after The Associated Press reported last month that Northern Mariana Islands government auditors had questioned whether the territory got its money's worth when it paid Abramoff's firm millions of dollars in the 1990s.

The payments included at least $1 million that his then-employer, the Preston Gates lobbying firm, failed to justify. Auditors quoted officials as saying they could save lobbying money by flying fewer members of Congress to the islands.

"I believe there is more than enough initial evidence to warrant a thorough and bipartisan investigation of Mr. Abramoff and potential congressional wrongdoing in the territories," Miller wrote in a letter to House Resources Committee Chairman Richard Pombo, R-Calif.

An Abramoff spokesman has said fees charged by the lobbyist and his firm were justified. Preston Gates (search) declined to comment on specific audit findings.

Miller has long sought to lift the islands' exemption from a range of U.S. labor and immigration laws, contending immigrants are facing widespread abuse. The islands' government hired Abramoff and Preston Gates in the 1990s to help fend off any possible changes.

Abramoff, a major fundraiser for President Bush's re-election campaign, is under investigation by a federal grand jury and the Senate Indian Affairs Committee for deals in which he and an associate received at least $66 million from six Indian tribes to lobby for their casinos and other interests. The tribes question whether the charges were excessive.

Congressional Democrats also are examining Abramoff's ties to House Majority Leader Tom DeLay, R-Texas, including foreign trips Abramoff arranged for DeLay.

The trips include one to the islands in December 1997. Abramoff organized DeLay's visit and the commonwealth government and Saipan Garment Manufacturer's Association (search) paid for it. DeLay said after the trip that he viewed the islands' clothing factories as a success and believed they should keep their exemption from U.S. labor laws.