Government watchdog groups criticized Sen. Ted Stevens (search) on Thursday following a newspaper report that the Senate's senior Republican had grown wealthy from investments with people who benefited from legislation he helped write.

The conservative Citizens Against Government Waste (search) said the Alaskan should resign as chairman of the Senate Appropriations Committee and the group sought an investigation by the Senate ethics committee. The organization frequently has criticized Stevens for steering billions of federal dollars to his home state.

Scott Milburn, spokesman for the committee's chairman, Sen. George Voinovich, R-Ohio, declined comment.

In one instance examined by the Los Angeles Times, Stevens invested $50,000 in real estate partnerships that have grown in value since 1997 to between $750,000 and $1.5 million.

Stevens was made a partner in those investments by Anchorage developer John Rubini (search). Stevens helped Rubini keep a $450 million contract with the Defense Department for housing on Elmendorf Air Force Base near Anchorage, the Times reported.

In August, the Anchorage Daily News reported similar details about Stevens' successful investment with Rubini.

"You have to admit, (it) is a hell of a return on the investment for what I put in it," Stevens told the Anchorage newspaper at the time.

Rubini did not return a call Thursday.

The Times said Stevens' brother-in-law, lawyer and lobbyist William H. Bittner, has been in the middle of many of the deals.

"What this whole thing points to is the need for both chambers of Congress to have stronger ethics laws, and do a better job of policing themselves," said Mary Boyle, spokeswoman for the liberal group Common Cause.

Stevens' spokeswoman, Courtney Schikora, said the senator would not comment on the newspaper report.

But in a written statement on his real estate investments to the Los Angeles paper, Stevens said, "I am a passive investor. I am not now nor have I been involved in buying or selling properties, negotiating leases or making other management decisions."

He also said his actions were motivated by a desire to help his state.

Stevens, 80, has been in the Senate for nearly 35 years, longer than any other current GOP senator.

In an interview, Bittner said nearly every Alaskan has asked Stevens for help during his long career. "More times than not, he says no rather than yes," Bittner said.

He added, "I think the reporters wanted to write a certain kind of story, and they wrote it to insinuate that Stevens became wealthy doing favors for friends. If you read it carefully, the facts don't point to that at all."

The Appropriations Committee that Stevens heads controls spending by all federal agencies and about one-third of the government's $2.2 trillion budget. He has aggressively used his post to funnel money to his home state, as do many members of that committee.