Martial-arts master Steven Seagal is a "delusional" liar, witnesses testified yesterday in defense of a reputed wiseguy accused of trying to squeeze millions out of the action-flick actor.

"His ability to be truthful is questionable, very much so," said Canadian filmmaker Damian Lee, when asked to describe Seagal's reputation in the movie world.

Lee was one of seven witnesses reputed Gambino capo Anthony "Sonny" Ciccone's lawyer George Santangelo called to blast holes in the feds' version of the Seagal extortion saga.

The 50-year-old star -- who testified at the Peter Gotti racketeering trial earlier this month -- claims a group of wiseguys headed by Ciccone tried to muscle their way into the film industry by extorting him.

Seagal has accused his former producer Julius Nasso of teaming up with the thugs after their partnership dissolved, and trying to force the martial-arts master to keep making action flicks -- and shell out $3 million.

The aging action hero said the Gambinos expected a cut of the profits.

"Delusional, that would be a fair way of putting it," Lee told The New York Post outside court, describing Seagal's mental state. "You can't tell what is fact or fiction."

Another witness who testified yesterday said Seagal once convinced Nasso, a Staten Island resident, to jump on a red-eye flight because the star's California estate was under siege by Japanese "yakuza" gangsters.

James Daluise, a friend of Nasso's, said he accompanied the producer on the bizarre emergency trip. By the time the pair arrived in California, Seagal calmly told them it was "a mistake."

In an angry courtroom tirade, reputed mob boss Peter Gotti accused prosecutors of using him as "window dressing" in their racketeering trial -- and ranted that the feds are secretly plotting to slap him with new charges if he beats this case.

"If there's a God above . . . and I beat this, how long will it be before there's another [case]? Two or three weeks?" the gruff-voiced Peter fumed. "Find someone else to waste your money on. This is window dressing!"

Peter unleashed his fury on a prosecutor and an investigator who remained in the courtroom after Brooklyn federal court Judge Frederic Block and the jury left on the last day of evidence presentation.

And the accused Gambino big wasn't just blowing off steam -- he wanted answers.

"C'mon, you can answer. There's no one around," Peter shouted at special Assistant U.S. Attorney Rick Whelan, who did not respond and averted his eyes from the ranting wiseguy.

Peter -- who is on trial with six other alleged mobsters, including his brother Richard V. Gotti and his nephew Richard G. Gotti -- faces money-laundering charges for allegedly taking a cut of various Gambino rackets as boss of the crime family.

Plea talks prior to the trial failed because federal prosecutors in Manhattan refused to give Peter protection against any new charges.

Brooklyn federal prosecutors mounted a circumstantial case, showing jurors dozens of photographs and a blurry surveillance video of Peter's regular meetings with his alleged bag man Jerome Brancato, among other evidence.

In one case, Brancato climbed into Peter's Ford Expedition carrying a bag -- allegedly containing money -- and came out empty-handed. But investigators never saw money change hands.

Lt. Stephen Mutone, an investigator with the Waterfront Commission who documented a March 28, 2001, meeting between Peter and Brancato on an extremely blurry video, bore the brunt of the reputed Gambino boss's most scathing remarks yesterday.

"All the times you followed me, why didn't you search me? You should be embarrassed!"

Defense lawyer Gerald Shargel said he intends in his closing argument later this week to "deflate the circumstantial-evidence case" by showing that prosecutors "cherry-picked" their wiretap recordings to suit their version of the facts.

"They have not given a complete picture," Shargel said outside of court.