Friends of Sen. Ted Stevens (R-Alaska) discussed ways to cover up the fact that former oil company executive Bill Allen was paying a plumber to repair the heating system at Stevens’ house, according to tapes of telephone conversations between Allen and others that the FBI secretly made and played for a jury on Tuesday.

Stevens has been accused by the government of accepting more than $250,000 worth of gifts — mostly in the form of repairs to his home — which he did not report as required on his annual financial disclosure forms.

Prosecutors on Tuesday called to the witness stand a plumber who repaired the heating system at Stevens’ house in Girdwood, Alaska.

The plumber, Charlie Hart, testified that he had been called to Stevens’ home in January 2006 to repair the heating system. He said he prepared two bills as directed by Allen — one for $1,118 for materials, which was sent to Stevens, and a second for $1,080 for labor, which was sent to Allen.

The bill sent to Stevens included a notation “labor paid by Bill.”

In a series of February 2006 telephone conversations that were played for the jury, Allen, his secretary and Bob Persons — a friend of Stevens’ who was overseeing the renovation on his home — discussed Stevens’ reaction to the bill, and his demand that he be allowed to pay the full cost of the repair.

Though Allen had not yet been contacted by the FBI, Persons and Allen were clearly aware that investigators were looking into Stevens’ finances.

“We’ve got to be real careful,” Allen told Persons on the tape, and Person’s agreed that “they are raking him over the coals about anything they can.”

Persons apologized to Allen for letting Stevens see the bill that indicated Allen had paid the labor costs on the repair, then suggested a way to get rid of that bill. “We don’t need this thing floating around,” Persons said. “We need to make the guy from [the plumbing company] make that disappear from his records.”

The two men ultimately concluded the best way to resolve the problem was to get Stevens to write a check to Allen to cover the cost of the labor, a check which Allen would not cash.

“Then if it ever comes up,” Persons suggested, Allen could simply say “here’s a copy of the check.”

One of the tapes included a conversation Allen had with his secretary in which she explained that Stevens had sent an e-mail raising concerns about the labor costs that Allen paid.

“He said, ‘I should pay those plumbers,’” she told him.

Allen and Parsons also discussed a racehorse partnership that they were involved in with Stevens, and joked about Stevens’ concerns about money.

Persons said that the Senator’s wife had told him “Ted gets hysterical when he has to spend his own money.”

The prosecution is expected to call its final witnesses Wednesday morning, and Judge Emmet Sullivan said he expects to dismiss the jury at lunchtime so that he can hold a hearing on Stevens’ Sunday motion to dismiss the case.

Stevens’ attorneys have argued that the prosecution intentionally withheld information from them that could have been helpful in Stevens’ defense. While the prosecution has admitted that some evidence was inadvertently turned over to the defense late, the government maintains that these errors were neither a violation of their duties nor a significant impediment to Stevens’ defense.