The trial for a Calgary man charged with murdering his partner and attempting to hide her remains began in a Calgary courtroom on Tuesday.

Allan Shyback, 40, is charged with second-degree murder and causing an indignity to a body in connection with the death of Lisa Mitchell, 31, his common-law wife.

Shyback pleaded not guilty to the charges and on the first day of the trial, the court heard from Mitchell’s mother, Peggy, who said that the pair had a rocky relationship and were ‘on and off’ for about 10 years.

Peggy Mitchell told the court that there was a domestic incident at the couple's Ogden home a few months before Lisa disappeared and that she hit Shyback with a frying pan.

She says Lisa moved out but that the couple reconciled a short time later.

Mitchell says Shyback told her that he had gone to the store and that when he returned about 20 minutes later she was gone.

She says she received a voice mail at 2:45 a.m. on November 15, 2012 from a woman who said ‘Hey. I’m Okay.’

Mitchell says her daughter wouldn’t have called her at that time and that her words were ‘totally, totally off.’

She told the court that the last time she saw her daughter was in October 2012 and that she was the one who reported her missing to RCMP.

In an agreed statement of facts, Shyback admitted to using previous recordings of his wife’s voice to create the messages that were left on Mitchell’s phone.

Police arrested Shyback on December 6, 2014 and a search warrant executed at the home uncovered Mitchell’s remains hidden in the basement.

Investigators say Shyback had kept them there following her death in 2012.

The Crown says Shyback confessed to undercover officers that he strangled Lisa and then buried her body.

"The accused took significant steps to cover up the death and cover up his role in the death. At the end of the day, the Crown will prove the accused intended to cause the death of Lisa Mitchell," said prosecutor Heather Morris in her opening statement.

During a search of the home police also recovered a data disc that contained eight conversations and Internet history on the home's computer showed searches on body decomposition and murder legislation in Canada.

The trial is expected to continue until the end of next week.

(With files from The Canadian Press)