PORTLAND, Ore. (AP) - House Democratic Leader Nancy Pelosi Sunday called for an ethics panel investigation of Rep. David Wu following a published allegation that a young woman reported he'd engaged in "aggressive and unwanted sexual behavior."
The Oregon Democrat has been facing calls to resign, but he remained silent Sunday.
In a statement Sunday night, Pelosi asked the "Ethics Committee to initiate an investigation into the allegations against Congressman Wu."
Pelosi had a telephone conversation with Wu Saturday but neither politician disclosed any details.
The Democratic leader says she will send a letter to leaders of the Republican-led House Monday formally asking for the probe.
Wu's spokesman Erik Dorey said he couldn't comment immediately on Pelosi's statement and thatn Wu may make a statement Monday.
Earlier Sunday, Dorey said he couldn't disclose what Wu did during the day or who he might have consulted.
A Democrat who has challenged Wu in next year's primary, state Labor Commissioner Brad Avakian, said Wu should see Pelosi's calls for an ethics investigation as a signal to step down immediately.
"An ethics investigation would result in a long drawn-out distraction and prolong the public pain" for the unidentified woman who has accused Wu, Avakian said through his spokesman, Jake Weigler. "For the sake of our community and this young woman and her family, as well as his own family, David Wu should do the right thing and step aside now."
Another Wu challenger in the Democratic primary, state Rep. Brat Witt, said an ethics investigation is needed so "we get to the bottom of the allegations and determine what the facts are."
Wu's only response so far has been a brief statement late Friday: "This is very serious, and I have absolutely no desire to bring unwanted publicity, attention or stress to a young woman and her family."
Oregon Democrats have been waiting for word on how Wu plans to respond further to the allegation and the resignation calls.
Spokesmen for both Gov. John Kitzhaber and the statewide party organization said Wu hadn't reached out to top Democrats in Oregon.
"At this point, I don't believe those conversations have happened," said Trent Lutz, executive director of the state party.
Lutz and other party members said they hoped Wu would respond directly to the allegation reported by the Oregonian newspaper. The paper quoted sources who said a young woman left voicemail at Wu's Portland office earlier this year accusing him of an unwanted sexual encounter three weeks after last year's election.
Citing anonymous sources, The Oregonian reported that Wu told senior aides that the sexual encounter 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.
In Wu's district stretching from downtown Portland to the Pacific Ocean in northwest Oregon, county-level leaders said they, too, were hoping for more from Wu.
"I'm waiting for more details to come out," said Cris Land, party chair in Columbia County.
The heart of the 1st Congressional District is Washington County, a center of high tech and suburban development and the home of David Robinson, a former Navy officer and municipal official who lost by a margin of 4-1 to Wu in the Democratic primary last year. Wu faces primary challengers next year, as well.
Robinson said Sunday he will ask fellow activists in Washington County on Wednesday to approve a vote of no confidence in Wu, calling the woman's allegation "just another in a long line of disappointments and improprieties."
Wu has won seven terms. In 2004, he won despite acknowledging a decades-old college incident in which he tried to force a former girlfriend to have sex. Voters said they disliked an opponent's attempt to use that against Wu.
In January this year, seven staffers resigned because of behavior that included sending a photo of himself in a tiger costume to a staff member and an angry public speech. Wu attributed those to a period of mental health challenges that began in 2008 as marital issues led to separation from his wife.
Associated Press writers Terrence Petty and Nigel Duara in Portland, Ore., contributed to this report. Kevin Freking reported from Washington, D.C.