Congressman David Wu, who earlier this year apologized for bizarre behavior during his most recent re-election campaign, was facing calls for his resignation on Saturday over yet another crisis -- a young woman's reported accusation that she had an "unwanted sexual encounter" with the Democrat three weeks after his election victory in November.

Wu's spokesman, Erik Dorey, said the seven-term Democrat had a telephone conversation on Saturday with House Democratic Leader Nancy Pelosi about the allegation, which was first reported by The Oregonian newspaper. Dorey would not comment on the substance of the conversation

An aide to Pelosi declined Saturday to comment on Wu.

The allegation seemed to be boiling into yet another sex scandal confronting a member of Congress. It comes a month after Rep. Anthony Weiner, D-N.Y., stepped down after getting caught sending suggestive pictures of himself on his Twitter account.

Late Friday, the 56-year-old Wu issued a one-sentence statement about The Oregonian's report: "This is very serious, and I have absolutely no desire to bring unwanted publicity, attention or stress to a young woman and her family."

Pressure was building on Wu to publicly address the allegation. There were also calls for his resignation.

"I'm saddened to hear this news. David owes the citizens he represents a detailed explanation," said State Rep. Brad Witt, who is running against Wu in the Democratic primary next spring. "If this accusation proves to be true, it's time for David Wu to resign and get the help he needs."

Another challenger of Wu in the Democratic primary, state Labor Commissioner Brad Avakian, said Saturday Wu should resign immediately.

"I think any 56-year-old man, especially a 56-year-old Congressman, that asserts himself like this on an 18-year-old girl, has got no business serving in Congress," Avakian said at a news conference. "There is nothing that can be explained that makes this situation right. He's got to resign."

Former Oregon Secretary of State Bill Bradbury, also a Democrat, called on Wu to step down now.

"Obviously I think the right decision would be to resign," Bradbury told the AP. "I felt that way (after previous reports of erratic behavior) and I feel that even more strongly now."

Earlier this year Bradbury announced he was supporting Avakian, and at the time called Wu "damaged goods."

Tom Chamberlain, Oregon AFL-CIO president, wouldn't speculate on Wu's chances to get the powerful labor group's nod in the 2012 election, as Wu has in past elections, but said "it's a high threshold."

Still, Chamberlain said "it's too early" to say whether Wu should step down.

Citing anonymous sources, The Oregonian reported that Wu told senior aides that the sexual encounter last November with the young woman in California was consensual. The paper reported Facebook notes indicate she graduated from high school in 2010 and that she registered to vote in California last August.

The paper said the woman decided not to press changes because there were no witnesses and it would have been her word against Wu's.

The newspaper said its information came from multiple sources familiar with the allegation.

The Oregonian's report adds new troubles for a congressman who fought accusations of strange and erratic behavior during his re-election campaign last year. Seven members of his re-election campaign quit in January because of behavior that included sending a photo of himself in a tiger costume to a staff member and an angry public speech.

Earlier this year, Wu told the AP that his erratic behavior last year was the culmination of a period of mental health challenges that began in 2008 as marital issues led toward separation from his wife. The couple's divorce proceedings are ongoing.

In a 2004 re-election bid, Wu acknowledged a decades-old college incident in which he tried to force an ex-girlfriend to have sex. His opponent in the general election tried to use the report from Wu's undergraduate days at Stanford in 1976 to show Wu wasn't fit to serve. Instead of derailing his campaign, the opponent's tactics were regarded as unseemly, and Wu won re-election handily.

Wu and his wife separated in December 2009 for reasons that have not been disclosed. They have two children.

Oregon's Democratic leaders were reluctant to discuss the latest allegation on Saturday.

"We're waiting to see what happens," Trent Lutz, executive director of the Democratic Party of Oregon, told the AP.

The Oregonian quoted sources as saying that a distraught young woman called Wu's Portland office earlier this year and left a voicemail accusing him of an unwanted sexual encounter in Southern California three weeks after last year's election.

The paper said the woman is the daughter of a high school friend of Wu's who has donated to the congressman's campaign.

Wu represents Oregon's 1st Congressional District, which includes part of Portland and stretches northwest to the Pacific Coast.

Wu was first elected to Congress in 1998. Each election cycle he is a prime target for the Republican Party, but he keeps disproving predictions that he will lose.

He has shown an unpredictable streak that has baffled some fellow Democrats. He sided with House Republicans in 2003 and voted for President George W. Bush's Medicare bill, then drew some attention at home for opposing now-former Gov. Ted Kulongoski, a fellow Democrat, who agreed to allow the Warm Springs tribe to build an off-reservation casino in Cascade Locks.

In a speech on the House floor in January 2007, he referred to people in the Bush White House as Klingons.

Congress has had a run of scandals that have led to resignations in recent months.

The month before Weiner's departure, Sen. John Ensign, R-Nev., resigned in the midst of a Senate Ethics Committee investigation that was looking into steps that he took to cover up an affair with a former member of his campaign staff.

In February, Rep. Christopher Lee, R-N.Y., abruptly resigned after a gossip website reported that he had sent a shirtless photo of himself to a woman he met on Craigslist.