WINNIPEG -- Manitoba Justice has quashed child sexual assault allegations made by Winnipeg police against convicted murderer Karl Wesley McKay, who is currently serving a life sentence in the horrific killing of five-year-old Phoenix Sinclair.

Charges of sexual assault and uttering threats McKay faced have been stayed by the Crown, court records show.

The charges were dropped prior to them being formally sworn in court. The Crown will not proceed with a prosecution if they determine there's no reasonable likelihood of conviction or it's not in the public interest.

Late last year, a Court of Queen's Bench judge ordered McKay removed from an Alberta prison in order to return him to Manitoba to face trial.

Police previously said they began investigating McKay in March 2011 after a former girlfriend alleged her daughter had been sexually abused when she was seven years old, sometime between Jan. 1 and Dec. 31, 1997.

Cops said they interviewed the now 21-year-old victim while she was in custody and were granted an arrest warrant for McKay last October. They classified the alleged offence as a "major sexual assault." The Crown has until Jan. 24 to reinstate the charges.

McKay and his former common-law wife, Samantha Kematch, were convicted of first-degree murder in 2008 in the death of Phoenix, Kematch's biological daughter.

Phoenix was a ward of Child and Family Services for much of her short life until Kematch regained custody of the girl less than a year before her death on Fisher River First Nation in June 2005.

During that time, Phoenix was subjected to horrifying abuse. Court heard Kematch and McKay routinely beat the girl, forced her to eat her own vomit and confined her to a cold barren basement.

When Phoenix finally died from the abuse, the couple buried her body deep in an unmarked grave in the bush. They continued to collect welfare benefits in the girl's name and tried to pass off another girl as Phoenix to a social worker.

It was McKay who led RCMP to the remote area where she was buried.