WASHINGTON—A longtime friend of Alaska Sen. Ted Stevens crossed the powerful lawmaker Tuesday and testified that he gave the Republican senator thousands of dollars in gifts.

The fiercely loyal Stevens gave no indication he even saw former fishing and drinking buddy Bill Allen enter the courtroom, and the two men barely looked at each other as Allen testified about the expensive gifts he gave Stevens during their 26-year friendship.

Stevens, 84, is on trial for failing to disclose about $250,000 in gifts and favors on Senate financial documents.

“That’s Ted, right over there,” Allen said, pointing across the crowded courtroom to an expressionless Stevens.

At the heart of the case is a massive home renovation project in which Allen helped transform the senator’s small A-frame cabin into a two-story home with a garage, sauna, wine cellar and wraparound porches. There were other favors, too, said Allen, who founded the multibillion-dollar oil pipeline company VECO Corp. In late 1999, Allen said, Stevens feared that the Y2K computer bug would crash the power grid and leave his house in the dark. “So I went and got a generator and put it in,” Allen testified.

“Did he ask you for this?” prosecutor Joseph Bottini asked.

“Yeah, he said he needed a generator,” Allen responded, his head lowered, as he told jurors that Stevens never paid for the $5,000-to-$6,000 generator. At the apex of their careers, the two friends held nearly unrivaled power. Stevens was a master of the Senate, a beloved figure in Alaska who steered billions of dollars to his home state. Allen was a self-made millionaire who could summon state lawmakers to his hotel room for drinks and tell them how to vote. Wearing an electronic hearing aid and speaking slowly because of a head injury that followed a motorcycle accident, Allen at times seemed wistful about those days, and about his lost friendship. “We really liked each other, you know?” Allen said. “Ted really worked hard. Ted loved Alaska and I loved Alaska.” But the Justice Department corruption investigation targeting Stevens changed everything.

Confronted with overwhelming evidence against him, Allen turned on the senator. The last time the two men spoke, FBI agents were listening in. Since then, Allen has pleaded guilty to bribing Alaska lawmakers, sold his company and turned against his old friends in hopes of reducing his own prison time.

Prosecutors spent much of Tuesday trying to bolster Allen’s credibility by discussing a backbreaking career that took him from picking crops to learning to weld to running VECO.

Over the past few days, VECO employees have testified to working long hours at Stevens’ home south of Anchorage, building a balcony and a roof, installing a custom staircase and a generator, upgrading the electrical system and more. The complicated project involved raising the house on stilts and building a new floor below. Workers testified they were pulled off their regular jobs or received nighttime phone calls to work on Stevens’ house.

Allen spent 90 minutes on the stand Tuesday and was expected to spend most of Wednesday discussing the house project.