The government's star witness in the trial of Alaska Sen. Ted Stevens left the court for good on Tuesday, having finished a draining new round of testimony, before the prosecution team rolled out more audio tapes it seems to think will deliver a knock-out punch to the senator's cause.

And that star witness, former VECO CEO Bill Allen, was the also the star of these new tapes.

Now that he's been dismissed by the court, it seems the Stevens defense team will have a hard time countering what was heard by the jury late Tuesday afternoon on these tapes.

Allen, the one-time head of the now-defunct oil services firm, concluded his testimony just before the lunch break. He had been on the stand for a total of four days — and in Washington, D.C. for some three weeks. On Tuesday he endured his second day of cross-examination by lead defense attorney Brendan Sullivan before a short redirect by Joe Bottini, the U.S. attorney for the District of Alaska. He was then excused by the judge, and beat a hasty retreat to the door.

After lunch, however, the prosecution rolled out a purported smoking gun of sorts in the form of a plumber who performed work on the boiler at the Stevens' Girdwood, Alaska, ski "chalet." The plumber, Charlie Hart, had been flown to Washington at government expense to testify for about 10-15 minutes on how he billed Stevens for the parts used on the repair, but billed Allen $1,000 for the labor, at Allen's direction.

The central portion of the government's case focuses on the Girdwood chalet and some $188,000 in renovations the government said Allen and VECO performed on the dwelling. The government alleges that Stevens never paid for the work, though evidence has been introduced that shows Stevens asked on more than one occasion for bills. Allen admitted on the stand that he didn't bother to bill Stevens, and in some cases made work on the Girdwood chalet appear as if it had been done on his own house. He said he did so because he "liked Ted," and wanted to give him the renovation and other assorted items as a gift.

The government has structured its courtroom arguments to show that Stevens, while asking for bills, never pressed Allen, nor did he make an effort to pay.

The recordings introduced by the government this afternoon were made by the FBI Anchorage field office early in 2006, months before the bureau informed Allen he was under investigation and secured his cooperation against Stevens and others.

Regarding the work on the boiler, Stevens had been sent a bill by the plumbing company that plainly indicated Allen had paid for the labor. He e-mailed Allen, telling him that he (Stevens) needed to take care of those costs. Allen's secretary at VECO, Linda Croft, alerted Allen in a phone call that the senator was making inquiries.

Allen acknowledges what Croft is telling him in monosyllables, before changing the subject.

Later that same day — Feb. 16, 2006 — Allen spoke on the phone with Bob Persons, the owner of a Girdwood restaurant who acted as the point person on the housework in Stevens' absence.

Allen tells Persons of the e-mail from Stevens. Persons first voices some amount of confusion, before retrieving his own copy of the labor bill to see the "paid by Bill" notation for himself.

"Oh s--t," Persons says. "...Ouch. I didn't see that. I'm sorry."

"Oh f--k," murmurs Allen in response.

"It says 'labor paid by Bill.' Son of a b---h. You didn't want him to know," Persons says. "...We don't need this floating around."

"No!" says a suddenly animated Allen.

"We need to get to (the plumber) and make that disappear," Persons says. "... Tell that guy he needs to get rid of it."

"You know, I paid that other part," Allen says, thinking aloud. "Go down there and tell (the plumber) this was a mistake and get rid of the whole motherf----r."

Persons comes up with another idea. Have Stevens write him a check for the labor costs, Persons tells Allen, but don't cash it.

Allen says he likes this idea, and Persons continues to instruct him.

"Make a copy of the check," he says. Then, if someone comes around asking for proof of payment, show them the copy, Persons continues.

If someone asks if you deposited the check, Persons says to Allen, "Tell them 'I deposited it. I don't know where it went'."

The government told Judge Emmet Sullivan it plans to wrap up its testimony tomorrow. Sullivan, in turn, told the court he will hear arguments Wednesday afternoon on the latest push by the defense for a mistrial or a dismissal of the indictment against the senator.

The defense has repeatedly accused the prosecution of misconduct in the case, accusing the government's lawyers of not turning over evidence it believes is favorable to Stevens. Sullivan has already turned back two other defense moves to end the trial early.