A major Democratic fund-raiser was indicted yesterday on federal charges of hiring two New York City call girls to sleep with witnesses in a plot to thwart a federal investigation.

Charles Kushner, a New Jersey real estate mogul and the top donor to the Garden State’s governor, James Mc-Greevey, is accused of engaging a prostitute to have sex with a cooperating witness in a grand jury investigation – and having the sex act videotaped and sent to the witness’s wife.

That, and a failed attempt to seduce another witness, were part of a plan to threaten the government cooperators in an investigation into possible tax fraud and illegal campaign contributions, federal prosecutors said.

Mr. Kushner, who surrendered to the FBI yesterday morning, faces charges of conspiracy, obstructing a federal investigation, and promoting interstate prostitution.

His lawyer, Benjamin Brafman, released a statement disputing the charges.

“Charles Kushner is one of the most respected business leaders in the community and widely known as a very generous philanthropist,” the statement read. “The charges filed today are entirely baseless. Mr. Kushner is confident that once the facts are fully disclosed in a courtroom he will be completely exonerated.”

Mr. Kushner, 50, reportedly owns 20,000 apartments in New Jersey, builds between 500 and 1,000 new homes a year, and holds commercial properties in New York and throughout New Jersey. His firm, Kushner Companies, is worth $1 billion.

A generous philanthropist, he has funneled hundreds of thousands of dollars into the campaigns of Democratic politicians including Mr. McGreevey, President Clinton, Senator Clinton, Vice President Gore, and Senator Lieberman. He has also been the subject of accusations of improprieties in attributing his contributions from sources including his brother, Republican leaders, and government investigators.

The Federal Election Commission fined Mr. Kushner and 40 partnership entities he controls $508,900 last month, concluding an investigation into more than $500,000 in contributions the partnerships made without obtaining the agreement of the individual partners during the 1999-2000 election cycle.

According to the criminal complaint released yesterday, Mr. Kushner, aware of the U.S. Attorney office’s investigation since March of 2003, paid accomplices about $25,000 in cash last summer to catch one of the cooperating witnesses, a former employee and the husband of another witness, with a prostitute on videotape.

For about three months the scheme stalled because the accomplices failed to recruit a prostitute willing to lure the witness to have sex on videotape. Then Mr. Kushner took matters into his own hands, going to New York City and hiring a call girl with the promise he would pay her between $7,000 and $10,000.

A woman accepted the job, and in December she met with the co-conspirators in a motel in Bridgewater, N. J. There she was instructed to lure the witness, a former employee of Mr. Kushner, back to her room from a nearby location with a story of her car breaking down and needing a ride.

On the first attempt she failed to connect with the witness. The second time, he picked her up and drove her back to the motel. He did not go back to her room, but telephone numbers were exchanged.

One day later, she called him and he met her in a room with hidden videotapes rolling.

The tapes were delivered to Mr. Kushner, who, in a conference room at his company’s Florham Park, N.J., headquarters, watched the videos. Prosecutors said he was “satisfied” and ordered copies of the tape, along with still photographs. The tapes could be made public when Mr. Kushner comes to trial, authorities said.

Soon after, Mr. Kushner instructed the accomplices to make a similar videotape of the third cooperating witness, saying he wanted to be able to cause “problems and personal difficulties” if necessary.

Another call girl, a friend of the initial one, was engaged along similar terms. This time, though, the prostitute only succeeded in getting a ride back to the motel room. For her services she was paid $2,000.

The tapes remained with Mr. Kushner until certain associates of his received letters from the U.S. Attorney’s office indicating they were targets of a federal grand jury investigation.

Two days later, Mr. Kushner met with his co-conspirators and said he wanted the tape to be mailed from Canada to the witnesses’ wife and two children so it would arrive prior to a family party scheduled for the following weekend. The conspirators convinced him to mail the images only to the wife.

When the envelope arrived a few days later, the witness’ wife opened it and, according to the complaint, “discovered its contents.” Both witnesses turned the contents over to federal agents.

Senator McGreevey, who has received nearly 5% of the $7.9 million his campaigns have raised in the past decade from Mr. Kushner and his family members and employees, refused to comment. A spokeswoman said he was “saddened to hear the allegations.”

Mr. Kushner has emerged as a political heavyweight, recently joining Senator Corzine, a New Jersey Democrat, in an unsuccessful bid to buy the New Jersey Nets.

Mr. McGreevey appointed Mr. Kushner to the board of the Port Authority and later nominated him to become its chairman in 2002. That nomination stalled when accusations surfaced he had improperly used his businesses to become a massive political contributor in New Jersey.

Mr. Kushner resigned from the Port Authority board in February 2003, the same month a former employee filed a civil suit against him alleging widespread abuse and the federal investigation began.