Wife faces questioning over affair of the congressman and the missing intern

Investigators searching for the missing Washington intern Chandra Levy are to interview the wife of Congress- man Gary Condit, the man she was said to be having a "close friendship" with before she disappeared. "We're interested in anyone who can shed light on this case," said Terrence Gainer, an assistant police chief.

Despite intense pressure from Ms Levy's parents, the authorities have so far refused to treat her case as anything other than that of a missing person, saying there is no evidence for them to open a criminal inquiry. As such, they say, they have no suspects.

But since Ms Levy was last seen on 30 April, there has been increasing focus on her relationship with Mr Condit, a House Representative from California. Investigators have interviewed Mr Condit twice, though they stress he is merely helping them and is not under suspicion.

Earlier this week, Mr Condit is believed to have told those investigators he broke off the friendship with Ms Levy two days before she disappeared. Sources said the 24-year-old became distraught and refused to take no for an answer. In the 24 hours before she vanished, Ms Levy called Mr Condit several times, leaving messages on his pager. He never returned those calls.

Despite Mr Condit's insistence that he and Ms Levy were simply good friends, there is a widely held belief that there was more to their relationship. Sources had said that Mr Condit told investigators Ms Levy had spent the night at his apartment in north-west Washington on at least one occasion.

A close relative of Ms Levy is also said to have told police the intern had confided that she was romantically involved with the congressman. Ms Levy's landlord said the intern planned to give up the lease on her flat to move in with a boyfriend.

Adding to the intrigue over Mr Condit's private life is the claim from an airline flight attendant that she also had an affair with him. Anne Marine Smith, 39, who works for United Airlines, is believed to have told investigators she had an affair with Mr Condit. She said that last winter she became suspicious that the 59-year-old Democrat was also seeing another woman.

Mr Condit has remained silent, apart from issuing occasional statements of denial through his aides. He has refused to speak publicly about it. But yesterday his aides released a time-line, detailing Mr Condit's activities for the week Ms Levy went missing. On 30 April, it says the congressman was picked up by his staff, had lunch at the White House and worked on Capitol Hill for four hours before going home to dinner with his wife, Carolyn.

The following day, the time-line reports that Mr Condit had meetings with the Vice- President, Dick Cheney, journalists and constituents. He also voted in the House before again returning home for dinner with his wife.

Ms Levy's parents, Susan and Robert, who live in Modesto, California – within Mr Condit's congressional district – have hired former Washington detectives and a high-profile lawyer to help in the search. Their daughter was to return to Modesto on 9 May to collect her master's degree from the University of Southern California, having done a summer internship with the Federal Bureau of Prisons.

Commander Jack Barrett, chief of the team of Washington detectives, which with the FBI is investigating Ms Levy's disappearance, said there were three main theories they were working on: she ran off on her own, she was a victim of foul play or she committed suicide. "No theory holds any more weight than any of the others," he said.

Mr and Mrs Levy have appeared on television, urging the congressman to break his silence. On a "Find Chandra" web page, a reward of $25,000 for information leading to the safe return of Ms Levy was said to have been put up by "Friends, family and Congressman Gary Condit's office".