The body of Phoenix Sinclair, seen here in an undated photo, was discovered in March 2006 on the Fisher River reserve. (Family photo)

The Manitoba couple convicted of murdering a five-year-old girl must wait to learn whether their appeal is successful.

After two days of submissions that ended Wednesday, the three Court of Appeal judges reserved their decision in the case of Samantha Kematch and Karl McKay, who were convicted of first-degree murder in the 2005 beating death of Kematch's daughter, Phoenix Sinclair. They are not eligible for parole for 25 years.

Sinclair was killed in in the basement of a home on the Fisher River First Nation, about 180 kilometres north of Winnipeg. Her body was wrapped in plastic and buried in a shallow, unmarked grave near the garbage dump of the reserve.

This week, lawyers for the couple argued they should have been convicted on the lesser charge of manslaughter.

Under the Criminal Code, a slaying committed while forcibly holding someone elevates the crime to first-degree murder rather than second-degree murder or manslaughter. However, lawyers for Kematch and McKay argued the girl was not physically locked in the basement, and would frequently come upstairs to eat or play with siblings.

In his submission, McKay's lawyer, Mike Cook, suggested the young girl might have voluntarily stayed in the unheated concrete basement to get away from the beatings, chokings and other violence she suffered upstairs.

Girl routinely beaten

Kematch and McKay were convicted in December 2008 after a jury accepted that Sinclair was confined to the basement of the home. During the trial, defence lawyers did not deny the abuse but argued there was not enough evidence to convict the couple of first-degree murder.

Court was told at the trial that Kematch and McKay routinely beat Sinclair with their fists, feet and metal bars, and forced her to eat her own vomit. Sinclair was also choked until she passed out and was shot with a pellet gun.

The court was also told she had broken bones throughout her body when she died.

Her body wasn't found until March 2006, after police laid charges against Kematch and McKay and the latter showed RCMP the burial site.

At the appeal hearing this week, Crown attorney Rick Saull urged the judges to reject Cook's argument.

"[Phoenix] was down there because she was bloody well told to stay there, and she wasn't coming up," he said.

No date has been set as to when the panel of judges will render their decision.

With files from The Canadian Press