WASHINGTON (AP) - When it comes to oil and fish, few wield power like Alaska Sen. Ted Stevens.

The longest-serving Republican in Congress is a champion for his state's industries and has steered federal money to benefit workers in the oilfields and on the docks. Now, federal prosecutors are asking whether Stevens' son benefited, too.

Stevens is under scrutiny as part of a Justice Department corruption investigation. So far, the most public moment in the case - the FBI's raid on Stevens' home in July - was about oil. Authorities are investigating the senator's ties to a corrupt oil services contractor who helped remodel the house.

But authorities have also quietly amassed evidence about fishing. After serving subpoenas throughout the industry last year, investigators recently returned to Seattle, home to many of the boats and processors that bring Alaska's seafood to market.

Industry officials and attorneys involved in the case, who spoke on condition of anonymity because authorities have told them not to discuss the probe, said investigators are asking about federal legislation that directly or indirectly aided the senator's son, Ben, who is a state lobbyist and politician.

The legislation was passed as earmarks, brief spending items that lawmakers tack onto bills to steer federal money to pet projects. Ted Stevens, an unapologetic user of earmarks, is the biggest champion for Alaska's $2 billion-a-year seafood industry.

Stevens has said he won't discuss the investigation so it won't look like he's trying to influence it. His spokesman, Aaron Saunders had no comment and Ben Stevens' attorney did not respond to messages.

Among the pieces of Stevens-sponsored legislation being eyed:

-A $100 million federal loan program approved in 2000 to buy out Alaska crab boats, trim the size of the fleet and boost prices. The Bering Sea Crab Effort Reduction Fund, an industry group that supported the buyout program, hired Ben Stevens' company, Advance North, as a consultant.

-A $30 million earmark Ted Stevens used to create the Alaska Fisheries Marketing Board, which provided federal money to promote Alaska seafood. Ben Stevens was the board's first chairman and approved grants to companies including those paying him consulting fees, state financial disclosure reports show.

-A $50 million loan program, like the crab buyback, seeking to trim the Alaska salmon fleet in 2004. The Southeast Alaska Seiners Association, a salmon fishing organization, hired Advance North to help push the deal. Ben Stevens is not a federal lobbyist and the salmon fishing group said his business partner, Trevor McCabe, did the lobbying.

But Victor Smith, a fisherman and critic of Ben Stevens, gave the FBI a taped phone conversation that he said proves otherwise. In the 2005 conversation, Smith called the seiners group's board member Bryan Benkman to discuss why funding was stuck in the federal bureaucracy even after the earmark passed.

Both men expressed disappointment in Ben Stevens and Smith asked why he was hired. Benkman replied that the younger Stevens recalled his success getting the crab buyback passed and pitched himself as a conduit to his father.

"He said, 'Hey, see I've got a program. You know, I've got this one to my credit. Hire me, you know, I'll get Dad to fund you guys, too," Benkman said.

-A 2003 earmark that gave exclusive pollock fishing rights to Alaska natives in the far-flung Aleutian community of Adak. That meant millions of dollars for Adak Fisheries to manage the catch of pollock, the lucrative whitefish commonly used in fishsticks and fish sandwiches.

The company paid Ben Stevens $295,000 between 2000 and 2004, according to state financial disclosure reports. When the earmark went through, Ben Stevens also secretly held an option to buy into Adak Fisheries.

Questioned by the Anchorage Daily News in 2003, Ted Stevens dismissed any connection between the legislation and his son's consulting business.

"Neither one of us is getting rich. That's for damn sure," the senator said. "And we're doing what we think is right."

When the stock option surfaced in a lawsuit in 2005, the senator said he had never discussed the pollock bill with his son.

"I have all kinds of ownership in stock and real estate that my father doesn't have a clue about," Ben Stevens said at the time. "You don't tell your father every time you make a decision. I'm 46 years old."

Documents related to the earmarks were among those subpoenaed by authorities last year. At the time, however, Ted Stevens was not known to be a focus of the investigation. He has denied any wrongdoing and has not been charged with any crime.

Despite the criminal investigation, he remains extremely popular in his home state, where he has been a political figure since before statehood. Ted Stevens is up for re-election next year and has more than $1 million in campaign cash. His most recent fundraising quarter was strong and included tens of thousands of dollars from funds controlled by his fellow GOP lawmakers.