Facing a corruption scandal that has rocked the highest echelons of the Palestinian Authority in the West Bank, the Palestinian president suspended his chief of staff on Sunday while a committee investigates accusations that the aide sought to trade influence for sex.

A videotape broadcast by an Israeli television station last week shows the chief of staff, Rafiq Husseini, waiting naked in bed for a Palestinian woman who was said to have come to the president’s office seeking government help.

The accusations against Mr. Husseini, brought to light by a former senior Palestinian intelligence officer, have stoked a crisis of confidence in Palestinian leadership and led to accusations that the case was part of an Israeli plot to discredit the Western-backed Palestinian government.

The Palestinian Authority president, Mahmoud Abbas, established a committee on Sunday to investigate the accusations and suspended Mr. Husseini pending the results of the inquiry, expected within three weeks.

Mr. Husseini asserted his innocence, saying late Sunday at a news conference in Ramallah that the tape had been doctored.

The accusations, which date to 2008, were made public by Fahmi Shabaneh, a former intelligence official who said he was frustrated by corruption within the Palestinian Authority and the authority’s lack of action in the face of evidence of financial and sexual misdoings, the latter involving Mr. Husseini.

Mr. Abbas “promised to take measures within months," Mr. Shabaneh said Sunday in an interview at his Jerusalem home.

“But, in fact, he left Rafiq Husseini in his post,” he said.

Top figures from Mr. Abbas’s Fatah Party have accused Israel of having a hand in the scandal, saying that it was in Israel’s interest to undermine Mr. Abbas. And last week the Palestinian Authority issued an arrest warrant for Mr. Shabaneh on suspicion of collaborating with Israel.

An Israeli official, who was not authorized to speak publicly about the issue, said the Israeli government had nothing to do with the case.

While the Palestinian Authority has long been troubled by corruption accusations, the latest episode may qualify as the most sordid.

The woman in the video, who has not been identified, had gone to the president’s office to ask for help with a family problem, Mr. Shabaneh said. When Mr. Husseini responded with unwanted sexual advances, Mr. Shabaneh said, she complained to Mr. Shabaneh, who was then in charge of investigating corruption.

Mr. Shabaneh said he then set up a hidden camera sting in mid-2008 to prove to Mr. Abbas that Mr. Husseini was abusing his position. Mr. Husseini is also seen on the video disparaging Palestinian leaders.

In conservative Arab Muslim society, the sexual aspect of the case “is something shocking, an earthquake,” said Mahdi Abdul Hadi, an independent Palestinian analyst and director of Passia, a research institute in East Jerusalem.

“People are very angry,” he said, arguing that Mr. Abbas’s actions are “all coming too late.”

Mr. Husseini, who has not responded to phone calls from reporters, said Sunday night that he had been “ambushed by a gang that works for Israeli intelligence,” and that the “gang used the tape to blackmail me financially and politically.” He said the tape had been dubbed.

He had previously issued a statement calling the case a “conspiracy planned by two parties,” meaning his rivals within the Palestinian Authority and Israel. He said Sunday that the conspiracy was aimed at stopping his political work in Jerusalem.

Some personal score-settling may well have played a role. Mr. Shabaneh had faced charges in Israel of threatening Mr. Husseini. Those charges were later dropped but Mr. Shabaneh is still awaiting trial on charges of recruiting agents in Jerusalem to locate Palestinians who sold land to Israelis, and of membership in a Palestinian security apparatus while living in Jerusalem.

Under agreements with Israel, the authority is not allowed to operate in Jerusalem, which has also kept Mr. Shabaneh out of reach of a Palestinian arrest warrant.

Some of his allegations first surfaced in an interview with The Jerusalem Post published in late January.

Mr. Shabaneh, a lawyer by profession, said Sunday that he had kept copies of all his intelligence files, despite requests from his bosses to hand them over. He said he had dozens of files showing financial corruption from the Arafat era that the new administration has failed to deal with.

In addition, he accused the Palestinian leadership of nepotism that he says has resulted in almost all senior positions in the authority being staffed by Palestinians from the northern West Bank, at the expense of the south.

He has threatened to open up “more dangerous files” if those he has already exposed do not result in resignations or dismissals.

As for the accusations that he is playing into Israel’s hands, Mr. Shabaneh said he had left his law practice in Jerusalem to work for the authority because he wanted to help “build a Palestinian state of law and justice.”

“What they say does not concern me,” he added. “It is clear to the people. Corruption destroys our hopes for a state.”

Khaled Abu Aker contributed reporting from Ramallah, West Bank.