Natasha Cournoyer was last seen on Oct. 1. (CBC)

A $10,000 reward is being offered for information leading to the whereabouts of a Piedmont, Que., woman who has been missing since Thursday.

Natasha Cournoyer, 37, was last seen shortly after 8 p.m. leaving the Correctional Service of Canada office where she works in Laval's Chomedy district.

Cournoyer's boyfriend Michel Trottier said he believes his girlfriend was abducted.

"The more time goes by, the more this option grows," said Laval police Chief Insp. Andre Pyton.

"But, at this time we can't rule out any other options."

Video surveillance cameras at Place Laval where Cournoyer's office is located show her walking toward her car, but police can't tell if she ever made it, said Pyton.

She missed an appointment with her mother the next morning.

Unusual behaviour: boyfriend

Trottier, contacted authorities the following day and police found Cournoyer's car still parked in the lot near her workplace.

Trottier has been holding vigil at a command post set up near the building as police officers scour the area for clues.

"We are very anxious about what's going on," Trottier told reporters. "She has no enemies, she's not the kind of girl that she will go for a party for a few days.

"We wish she is safe some place. We wish that. She is a very courageous girl," said Trottier.

Laval police Lt-Det. Serge Vary said the relationship between Cournoyer and Trottier was "a bit ambiguous."

"They were together for four years, but had periods where they were off and on again," said Vary.

Authorities used a helicopter and police dogs to scan a wooded area near the federal agency building on Sunday.

Cournoyer worked as an internal communications officer for the Correctional Service of Canada, said Brigitte Dube, regional director for Quebec.

"She had no direct contact with offenders," said Dube.

Dube said the missing woman's co-workers are being provided with counselling.

The reward is being offered due to a partnership between Laval police and the community group Sun Youth.

The organization's director of emergency services, Tommy Kulczyk, said donations came from two anonymous donors – a father and a grandfather.

Police are asking anyone with information to call 450-662-4646.