CALEDON, Ont. -- Ontario Provincial Police have released a video to try to identify two people they say could be witnesses in the unsolved murder of a central Ontario woman.

Sonia Varaschin of Orangeville, Ont., was reported missing on Aug. 30, 2010, after she failed to show up at work. Her body was found days later in a wooded area in nearby Caledon.

Police say it's believed the 42-year-old nurse was murdered in her home, about an hour northwest of Toronto, and have said her car and home were stained with blood.

They've released surveillance video of a gazebo in a park behind Orangeville's town hall -- in an area close to where police say Varaschin's vehicle was left in the early morning hours of the day she disappeared.

The video -- which can be viewed on the provincial police YouTube page -- depicts two people in a gazebo prior to them walking away at about 6 a.m. that day.

Police say the two are potential witnesses and not suspects in the case and are asking anyone who recognizes them to contact the force immediately so investigators can identify and speak with them.

A reward of $50,000 was previously announced for information leading to the arrest and conviction of the person or persons responsible for Varaschin's murder.

The case drew national attention as investigators revealed the culprit likely left Varaschin's home covered in a significant amount of blood and used her car to move her body to the wooded area where it was found.

"Our investigators are as committed to finding Sonia Varaschin's killer today as we were when it began in 2010," said OPP Det. Insp. Shawn Glassford.

"We are determined to bring justice to Sonia and her family," he said.

"No tip is too small or insignificant in fact it could be the missing piece of the puzzle that we need to solve this case."