Officials decided to shut down decrepit building last year amid concerns that the air in the mansion was no longer safe to breathe

So many dead mice were trapped behind the sagging walls and heaped in the basement of the Canadian prime minister’s official residence that officials decided to shut down the decrepit building last year amid concerns that the air in the mansion was no longer safe to breathe, according to newly released documents.

The limestone-clad house at 24 Sussex Drive, perched on a cliff above the Ottawa River, is the country’s most symbolically important and politically fraught plots of real estate.

Allegations of attempted meddling by China put uncomfortable spotlight on publicity-shy CSIS

Most Canadians have no idea where the country’s spy agency is located, nor do they know much about its daily operations. This is not because the Canadian Security Intelligence Service operates in a particularly clandestine fashion, it’s because most Canadians don’t care.

The CSIS, a civilian-run organisation based in a triangular structure of concrete and glass on the outskirts of Ottawa, lacks the intrigue of Britain’s MI5 and the notoriety of America’s Central Intelligence Agency.