WASHINGTON (AP) — Police have asked Rep. Gary Condit to take a lie detector test and submit a DNA sample, and they plan to search his apartment for clues to the whereabouts of Chandra Levy, Washington Police Chief Charles Ramsey said Tuesday.

His comments came a day after Levy's mother asked Condit to submit to a lie detector and Condit's attorney, Abbe Lowell, said the congressman would volunteer a DNA sample and allow a search of the apartment.

"It's not saying he's a suspect or that we expect to find anything," Ramsey said. "We are doing the responsible thing and following up on (Lowell's) offer."

Ramsey would not discuss what police would be looking for during the search, but said "certain types of evidence do not degrade over time."

Ramsey said police have contacted Lowell to set up times for the search and to see if Condit will submit to the polygraph test and give the DNA sample. Ramsey said he hopes the search and test can be done in the next day or two.

On Monday, Lowell said that the reliability of lie detector tests is suspect, but that he would consider a request for such a test if it came from police.

Marina Ein, a spokeswoman hired by Lowell in this case, said, "Details will be worked out." Ein said Lowell was out of town Tuesday.

Condit, D-Calif., said nothing to reporters as he went into a meeting of conservative Democrats at the Capitol. Later, he cast votes on the House floor and chatted with colleagues.

Condit's lingering involvement in the police investigation has made for an awkward situation in Congress. When his fellow conservative Democrats held a news conference on energy policy, reporters eventually posed questions about Condit.

Rep. Max Sandlin, D-Texas, called Condit a "serious policy player." But when asked if he thought Condit should resign, Sandlin said, "I don't think that's my decision to make. That's a decision for others to make."

Levy, 24, of Modesto, Calif., was last seen April 30 when she canceled her membership at a Washington health club. Her internship with the federal Bureau of Prisons had just ended, and she was planning to return home to participate in graduation ceremonies at the University of Southern California.

Police searched her apartment and found nothing missing but her keys. Her bags were packed.

Last week, Levy's aunt said her niece told her she was having an affair with the 53-year-old Condit, who is married, and would often visit him at his apartment in Washington's Adams Morgan neighborhood.

During a third interview with Washington police on Friday, Condit acknowledged the affair, according to a source familiar with the investigation.

Condit hasn't spoken publicly about his relationship with Levy, but his office has denied an affair. In a statement, Condit has called Levy a "good friend."

Ramsey said despite three interviews with Condit, police still are seeking "clarity" on his relationship with Levy. He said the latest requests of Condit also could provide "comfort" to the Levy family.

In Modesto, Dr. Robert Levy, the missing woman's father, criticized police for waiting more than two months since her disappearance to search Condit's apartment.

"If that's what they want to do now ... 10 weeks ago would have been a good time," Levy said as he went for a walk around his neighborhood.

Ramsey said he doubted police could have obtained a warrant for a nonconsensual search of Condit's apartment. "However, this is different because we've been invited someplace," he said.

Police say they have no evidence of foul play and still classify the investigation as a missing persons case. They have said repeatedly that Condit is not a suspect in the disappearance and has been cooperative with authorities.

Ramsey reiterated that police have no particular theory about what happened to Levy, and that their investigation contemplates that she fell victim to a crime, committed suicide or intended to vanish. Ramsey said suicide becomes less likely as time goes by because no body has been found.