Pickton raised and slaughtered pigs at the Port Coquitlam farm as a part-time occupation until his arrest at the property in February 2002, and police believe he gave or sold processed meat products to friends and acquaintances.
Pickton, 53, is awaiting trial in the killings of at least 22 of more than 60 missing Vancouver prostitutes who disappeared over the past decade and are feared to have been murdered at the dilapidated farm 20 miles east of Vancouver.
"Given the state of the farm, and what we know about the investigation, we cannot rule out the possibility that cross-contamination may have occurred," B.C. provincial Health Officer Perry Kendall told reporters in Victoria.
"Cross-contamination could mean that human remains did get into or contaminate some of the pork meat," Kendall said.
Officials stressed that the farm's pig slaughtering operation was not officially licensed and he did not sell processed meat to retail outlets.
"There is no evidence we are dealing with anything other than a very specific localized issue, with a specific number of local people," said Cpl. Catherine Galliford of the Royal Canadian Mounted Police.
Kendall said he was not contacted by the police until last month when they asked a "hypothetical question' about the potential health risk. He issued the alert when they later said it probably happened.
Details of evidence from the farm were presented in court last year at Pickton's preliminary hearing, but a court order prohibits reporters who covered the hearing from publishing details of what they heard until it is used in his trial, which will likely not start until next year.
Police defended the timing of their contacting health officials, saying it was needed to protect the investigation, although they also acknowledged more people may have received meat from Pickton than they had originally thought.