OTTAWA - A Conservative Party staffer made a horrifying discovery late Tuesday morning, partially opening a package that contained what police say appeared to be a human foot.

The overwhelming stench from the package sent a staffer running to call police.

"Upon arrival, officers noted that the package possibly had blood stains on it," police said in a statement.

Ottawa fire service paramedics set up a temporary quarantine in the downtown Ottawa office tower.

"We had 10 people on the 12th floor who were isolated because one person was exhibiting signs of nausea," fire service spokesman Marc Messier said.

Messier added no one needed to go to hospital.

A hazardous materials unit was sent in and the major crimes unit has taken over the investigation.

Ottawa Police spokesman Const. Marc Soucy said the first step of the investigation is getting confirmation from the coroner it was indeed a human foot inside the package.

Speculation the foot could be related to a torso found in a heap of garbage in Montreal earlier Tuesday was dispelled by Montreal police.

The package was apparently mailed to Tory headquarters.

Conservative Party spokesman Fed DeLorey declined comment.

"The Ottawa police are investigating," he said in an e-mail. "All questions should be referred to them."

There are dozens of tenants besides the Conservative Party at the office tower, including several diplomatic missions.