Federal prosecutors in Washington are scrutinizing Sen. Ted Stevens' home remodeling project as part of a spinoff of an Alaska corruption investigation that has led to charges against lawmakers and contractors.

Until recently, the Alaska Republican appeared to be a peripheral figure in a broad Justice Department investigation into bribery, extortion and other corruption.

But Stevens, the longest-serving Republican in Senate history, recently hired lawyers and said the FBI told him to preserve documents. Prosecutors have questioned his friends and associates, including in some cases before a Washington grand jury, according to someone familiar with the case who spoke on condition of anonymity because grand jury matters are secret by law.

One of those witnesses was Bob Persons, a friend and neighbor of Stevens, according to the Anchorage Daily News, which first reported on the Washington grand jury. Persons oversaw Stevens' home expansion project while the senator was in Washington and was ordered to provide documents related to that work, the newspaper said.

Federal investigators in Alaska have also questioned businessman Bob Penney but his lawyer would not say what was discussed.

"Bob has been a very close friend of Ted Stevens for years. Beyond that I really can't be telling you anything," said attorney Bruce Gagnon, who said Penney has turned over documents and answered every question put to him. "Bob feels for Ted. It's distressing."

Stevens was traveling out of the country Monday and his spokesman only reiterated Stevens' previous comment, in which the senator said he has a policy against commenting on federal investigations.

Investigators have focused on a 2000 remodeling project that more than doubled the size of the senator's home in the ski resort town of Girdwood, about 40 miles south of Anchorage.

Contractors who worked on Stevens' remodeling have said the FBI asked them to turn over records from the job. One of them said the work was overseen by VECO, the Alaska oil services and construction company at the heart of the investigation. Two former company executives, CEO Bill Allen and Vice President Rick Smith, have pleaded guilty to bribing Alaska legislators.

One of the lawmakers under scrutiny was Stevens' son, Ben Stevens, a former Alaska Senate President. The younger Stevens was among several state lawmakers whose offices were raided by the FBI last year. He has not been charged and denies any wrongdoing.