An autopsy has determined that a lifeless newborn found in a parking lot on Christmas Eve was “alive at some point” but the cause of death is “undetermined” and the baby’s mother has not yet been located, according to Calgary Police.

Police were called at about 11:30 p.m. Sunday by a resident who found the body of a newborn in a parking lot behind a grocery store in the Bowness district.

Sgt. Martin Schiavetta said at a press conference Tuesday afternoon that no trauma was detected on the baby but further medical tests are underway and the cause of death is "still being looked at."

"Right now it’s undetermined," he said. "But we can say through medical tests that at some point the child was alive. We do not know if the child was alive at the time that it was placed in that parking lot."

“We want to speak to the mother,” Schiavetta said.

"We are very concerned about the mother's physical and mental state," he added.

Schiavetta said that it is "very unusual" that police "have not had a tip."

The child has been described as a baby girl with light complexion and dark hair.

Police say they are concerned for the mother’s wellbeing, as evidence at the scene suggested she may be in medical distress.

Schiavetta said Calgary police are continuing to search for the mother and told reporters that they have not received any tips on her whereabouts.

Police are focusing their search on the local area but are open to the possibility that the mother may not be from Calgary, Schiavetta said.

Anyone with information about this incident or the possible identity of the mother is asked to contact the Calgary Police Service at 403-266-1234, or Crime Stoppers anonymously through the following methods.

With files from The Canadian Press