VANCOUVER - A retired RCMP officer says police were forced to stop surveillance on now-convicted serial killer Robert Pickton after the Port Coquitlam, B.C. pig farmer was tipped off.

Mike Connor told the missing women's inquiry Monday he learned from a civilian employee that Pickton had become aware of police surveillance by Aug. 9, 1999 -- a development that affected the course of the investigation.

"We'd have to discontinue surveillance," said Connor, who was the first RCMP officer to investigate Pickton. "If he was aware of it he wouldn't be in our view, or my view, conducting criminal activity."

"And, in fact, was surveillance then discontinued within a few days," asked commission counsel Art Vertlieb.

"Within a few day I think, yes," said Connor.

Just how Pickton found out about the surveillance remains unclear, but Vertlieb read into the record part of a report by Jennifer Evans, deputy chief of the Peel Regional Police.

Evans conducted an external review of the Pickton murder investigation, and in her report stated that three people Connor had interviewed at the time had "a very close association to Pickton and were more than likely to talk to Pickton..."

The inquiry is looking into the police investigation that allowed the serial killer to continue murdering women even though he had been a prime suspect for years before his 2002 arrest.

Connor's initial request for police surveillance almost a year before that turned out to be eerily accurate to the outcome of the Pickton murder trial.

You said Pickton was believed to be picking up prostitutes and apparently taking them to his home where he killed them, commission counsel Art Vertlieb asked Connor.

"Correct," Connor replied.

"There's a statement that the subject intimated that he disposes of bodies in a food grinder and feeds the remains ...," Vertlieb said, leaving his sentence unfinished.

Connor agreed.

The form Connor filled out also said Pickton had numerous female purses and identification on the farm that he apparently used as trophies.

Connor said he received the information from a source who had heard second hand about the horror taking place on the farm.

Evidence revealed much later at Pickton's trial proved the source was incredibly accurate, but the 30 days of police surveillance turned up no proof that Pickton was trolling Vancouver's Downtown Eastside for his victims, most of them sex-trade workers.

Pickton was convicted of killing six women, but the DNA of 33 women was found on his farm.

Connor's source was Bill Hiscox, who told police he had learned the information from Lisa Yelds, who was a good friend to Pickton.

Connor said Yelds was a "cop hater" and a Nazi sympathizer, and they didn't think they would get the information from her unless they conducted an undercover operation.

Hiscox had volunteered in late 1998 to help with the undercover operation by introducing Yelds to an officer.

But weeks later Hiscox disappeared and nothing was done to get more information from Yelds.

"He had fallen off the map," Connor told the inquiry.

Pickton was already on Conner's radar because he had been arrested in the 1997 attack on a Downtown Eastside sex-trade worker on his Port Coquitlam, B.C., farm.

Charges of attempted murder and unlawful confinement were later dropped against Pickton.

Connor testified that he was told by the Crown that the case wouldn't go ahead because the victim was a severe heroin addict and without her testimony the likelihood of conviction wasn't there.

He admitted during his testimony that he regrets not pushing parts of the investigation.

"I think about this file daily," he said.

Connor said he's being treated for post traumatic stress.

"I failed to put the bad guy in jail, I just, I couldn't do it. For that I'm sorry. I did what I could."

His testimony came on the same day that a lawyer for several family members of missing women claimed the commission was enabling a police coverup of the Pickton investigation.

Cameron Ward complained many key documents had not been disclosed at the inquiry and no one mentioned that the lead Vancouver police investigator in the case has written a book.

Ward has applied to see the manuscript for the unpublished book.

"I need to assist you Mr. Commissioner in taking all steps necessary to ensure that this coverup is not perpetuated further," Ward told Commissioner Wally Oppal.

"I do believe that unless this commission exercises its powers and duty under the inquiry act, it will enable the police to coverup their involvement in these important matters."

Oppal, a former B.C. Appeal Court judge and former attorney general of B.C., bristled at the claim.

"That any such suggestion may have been made is disturbing," Oppal said. "There is absolutely no evidence that the commission may be 'enabling a coverup."'

Vancouver Police lawyer Tim Dickson said the department is at the inquiry in openness and good faith, wants all the facts to come out, and there's nothing resembling a coverup.