One of Canada's most infamous mass murderers, Pickton was convicted in 2007 of killing drug addicts and prostitutes and butchering their remains at his pig farm in the Pacific province of British Columbia.
He was convicted of killing six women whose partial remains were found on his ramshackle property near Vancouver. Government prosecutors dropped charges for an additional 20 murders after he was sentenced to life in prison.
Canada's correctional service said Pickton had died after being assaulted on May 19 in the Quebec prison where he had been serving his sentence. Following the assault, he was transported to hospital to receive treatment.
"We are mindful that this offender's case has had a devastating impact on communities in British Columbia and across the country," the service said in a statement.
The victims were among more than 60 women who disappeared from Vancouver's poor, drug-infested Downtown Eastside neighborhood over more than a decade until Pickton's arrest in early 2002.
The remains or DNA of 33 women, many of whom were Indigenous, were found on Pickton's pig farm in Port Coquitlam, about 25 kilometers east of downtown Vancouver.
In 2016, a book reportedly written by Pickton was pulled from Amazon within hours of it appearing for sale. In the book, the serial killer said he was innocent and had been framed by police, the Vancouver Sun reported at the time.
The publisher requested its removal from Amazon and apologized to victims' families.
