Early testing shows that a severed foot sent to the headquarters of Canada's ruling Conservative party, a severed hand found in another package and a torso found in a garbage heap in Montreal all come from the same man, Montreal police said Wednesday.

Police added they were closing in on a suspect.

"The suspect and victim knew each other," Montreal police Cmdr. Ian Lafreniere told reporters. "It isn't linked to organized crime."

The packages with the foot and the hand, found Tuesday in Ottawa, were mailed from Montreal. It wasn't clear why they were mailed.

Police discovered the severed foot after Jenni Bryne, a top political adviser to Prime Minister Stephen Harper, opened a bloodstained box at Conservative party headquarters on Tuesday.

When Bryne opened the box, a foul odor overcame the office.

"It was such a horrible odor. I'm sure many of us will not forget it," Conservative Party spokesman Fred DeLorey said.

Police said the package was addressed to the Conservative Party of Canada and not to a specific person.

Police confirmed Wednesday that they intercepted a second package containing a human hand at an Ottawa postal facility late Tuesday. Police wouldn't say where the package was addressed. Canada Post wouldn't comment on the two discoveries.

Ottawa police said they were consulting with counterparts in Montreal after a janitor there discovered a severed male torso in a suitcase in a heap of garbage behind an apartment building on Tuesday.

Police in masks have been going through the apartment building and zeroed in on a unit from which a rotten stench was drifting out, a building resident said.

In Ottawa, political staffers were keeping a nervous eye on the mail.

"It's very upsetting," Opposition New Democrat member Yvon Godin said. "It could be just one crazy person that did it, but at the same time we have lots of people unhappy in our country, the way the country is going."

Opposition Liberal member Justin Trudeau called the packages horrific.