VANCOUVER - A woman who helped run a Vancouver drop-in centre for sex workers says she reported one of serial killer Robert Pickton's victims missing, but believes she was lied to when an officer told her the woman was in rehab.

Elaine Allan, who ran the WISH drop-in centre from 1998 to 2001, told an inquiry into the Pickton case that she doesn't believe Tiffany Drew was ever in rehab.

Instead, Allan said she thinks she was lied to by a police force that was dismissive and uninterested in reports that sex workers were vanishing at alarming rates from the city's Downtown Eastside.

Allan said she was working at WISH in 1999 preparing to open for the evening when another sex worker named Ashwan came banging at the door.

Ashwan was frantic that she hadn't heard from Drew, her friend, since the night before. The pair had formed a buddy system in which they would keep in contact to ensure each other was OK -- a system Allan said was being used by many sex workers at the time because of a rash of disappearances.

Allan said she called Const. Dave Dickson of the Vancouver Police Department, who had been researching reports of missing women and was WISH's main contact on the force.

Allan said the officer visited the centre and spoke to her and Ashwan, but she said Dickson told her Drew had a reputation for taking off with clients and not to worry about it. He didn't take any notes, said Allan, and didn't take a formal missing person's report.

"He was very casual about it," Allan told the inquiry, which is examining why the police failed to catch Pickton.

Eventually, Dickson told her Drew was in rehab and had specifically requested not to be contacted by anyone from the Downtown Eastside for fear she would relapse, said Allan.

But Allan said she and Ashwan didn't believe the story.

The next time Allan heard any information about Drew was in 2002, when a local reporter called her with news that Drew's DNA was found on Pickton's farm in Port Coquitlam.

"The only explanation you have in your own mind for why he said what he said to you is that he lied to you, didn't he?" asked Cameron Ward, a lawyer for the families of 18 missing women, including Drew.

"He lied to me," replied Allan.

Allan's account stands in contrast to Dickson's reputation in the Downtown Eastside, where he has become known as an officer who was among the first to seriously investigate reports of sex workers disappearing.

A lawyer with the inquiry confirmed Tuesday that Dickson will be called to testify. His notes, including those related to Drew's disappearance, have also been disclosed to the inquiry.

Pickton was initially expected to stand trial on murder charges involving 26 women, including Drew, but his trial was split into two parts, with six counts heard first and the remaining 20, which included Drew's case, to be heard later.

He was convicted of six counts of second-degree murder, and the Crown decided to stay the outstanding 20 charges because Pickton had already received the maximum sentence. The remains or DNA of 33 women were found on Pickton's farm, and he claimed to have killed 49.

Allan said she knew or had met 20 of the women linked to Pickton's farm, many of whom were regulars at WISH.

The inquiry has already heard allegations that police were quick to dismiss reports that women were disappearing, suggesting some of them may have moved away or gone on vacation to places as far away as Mexico.

But among residents and support workers in the Downtown Eastside, Allan said it was plainly obvious that something terrible was happening.

"It was sort of this dark force out there, it's like there was this monster out there," said Allan.

"You could feel the presence of this evil force that seemed to be swallowing up women, but we couldn't really figure out what it was."

The hearings are expected to continue for months, with commissioner Wally Oppal's final report due by June 30 of next year. Along with the work of the Vancouver police and the RCMP, the hearings will also examine the decisions by Crown counsel not to prosecute Pickton for attempted murder after an attack on a sex worker in 1997.

Among the dozens of witnesses still to testify will be sex workers from the Downtown Eastside. Oppal will hear an application this week to provide such witnesses with a number of protections, including publication bans to shield their identities and measures to ensure they don't face aggressive cross-examination.

The lawyer for the victims' families will also ask for a temporary adjournment later this week to give him more time to read documents before officials with the Vancouver police testify.