Prosecutors turned up the heat on Raj Rajaratnam yesterday, telling the jury in a searing five-hour closing argument that the hedge-fund titan was not only guilty of insider trading, but that his willingness to pay lavish sums to his “friends and employees” turned others into criminals.

Evoking multimillion-dollar payments made to Anil Kumar and Rajiv Goel, two former pals who have both pleaded guilty in the high-profile case, prosecutors said he was a corrupter of others.

Rajaratnam, 53, “corrupted well-connected friends and employees” as part of his plan to “conquer” Wall Street, Assistant US Attorney Reed Brodsky said in his last chance to win over the Manhattan federal court jury.

“It wasn’t always about the money,” Brodsky said. “It was about being on top. It was about beating everyone else.

“Cheating became a part of the business model,” Brodsky said, as part of the government’s finishing touches on the seven-week trial, one of the most-watched white-collar criminal cases in a generation.

Prosecutors pushed the envelope and used wiretaps on Wall Street for the first time — taking a clue from their success in organized crime trials. In that vein, Brodsky encouraged the jury to zero in on what he described as the “most “powerful” and “devastating” evidence in the case: “the defendant’s own voice.”

The use of dozens of wiretaps were controversial but allowed the government to use Rajaratnam’s voice in discussions with co-workers and friends allegedly showing him sharing and receiving illegal stock tips. The billionaire did not testify on his own behalf.

Brodsky re-played several of the tapes for the jury yesterday, and repeatedly asked them to refer to the tapes in their deliberations. “The tapes offer devastating evidence of the defendant’s crimes in real time,” he said.

The jury’s decision in the high-stakes trial, which kicked off on March 9, will have major implications for how business is done on Wall Street, including whether federal prosecutors, like Manhattan US Attorney Preet Bharara, continue what he calls the war against “pervasive” insider trading on Wall Street.

The defense was quick to fight back.

“The government’s case rests on a fictional idea that information can never become public until the company makes an announcement,” said Rajaratnam’s lead lawyer, John Dowd — getting right to the heart of the defense’s argument, which is that Wall Street is so chock-full of leaks the alleged tips were immaterial.

“This is the media age That’s ridiculous,” he said.

Dowd called on the jury to acquit Rajaratnam of the charges if they determine the alleged tips were already in the public domain. “If it’s public, you must acquit,” he said, slamming his palm on the lectern.

Dowd continues with his closing arguments today, followed by a rebuttal from the prosecution.

The jury is expected to start deliberations on Monday following instructions from Manhattan federal judge Richard Holwell on how to apply insider-trading laws to the charges. kwhitehouse@nypost.com