Facebook selfie helps convict Canadian woman Cheyenne Rose Antoine of killing friend Brittney Gargol

A Canadian woman has been convicted of killing her friend after police spotted the fatal weapon in their Facebook selfie.

Detectives spotted Cheyenne Rose Antoine, 21, wearing the belt used to strangle 18-year-old Brittney Gargol in the photo taken hours before the killing at a landfill site.

Antoine was sentenced to seven years in jail on Monday after pleading guilty to the manslaughter - though she claimed to not remember the killing.

She had also used social media to try to distance herself from the crime after the night out in March 2015.

Antoine had sent a message to her victim on Facebook the next morning, writing: "Where are you? Haven't heard from you. Hope you made it home safe."

The belt was used to strangle Ms Gargol. Credit: Facebook

Antoine later told police the pair had separated after visiting several bars when Ms Gargol headed off with a man and she went to visit her uncle.

But the killer went on to confess to a friend she hit and strangled Ms Gargol during a heated argument after consuming alcohol and marijuana.

Meanwhile detectives linked her to the scene with the use of the Facebook selfie after the belt was found next to Ms Gargol's body.

Antoine ultimately accepted responsibility but within her plea said she did not remember the actual killing.

"I will never forgive myself. Nothing I say or do will ever bring her back. I am very, very sorry... It shouldn't have ever happened," Antoine said in a statement.

Legal representatives for Antoine said she had suffered years of abuse in the Saskatchewan care system and had reported being abused by her foster parents one month before to police.