Public health authorities in Montreal have ordered the inspection of a squalid Park Extension apartment building following a resident's complaint.

Authorities believe mould and water infiltration pose a serious health risk, and they've already told resident Malik Ali to move his family out.

Ali, his wife and their four children have been living in the building on Stuart Avenue since July. The walls of the apartment, the ceiling, their clothes and their furniture are covered in mould, and Ali's asthma has become chronic.

The building is registered to Patricia Di Giambattista and Claudio Di Giambattista. Claudio has a long history of tenant complaints. The city has shut down other buildings he owns that have been deemed unsafe to live in.

Resident Malik Ali shows the mould growing in his apartment, where he lives with his wife and four children. (CBC)Calls to the Di Giambattistas were not returned.

'An old ploy'

Ali said Claudio Di Giambattista has threatened him and claims he's responsible for the mould.

"He just called me today and threatened me, and told me he's going to call the police. [Di Giambattista said] I'm going to put you in jail because he says I brought the thing in the apartment myself," said Ali.

City Councillor Mary Deros said it's an old ploy. She visited the apartment Tuesday and met with Ali.

"They're afraid to come and say my house is in bad shape because they may be threatened. (Landlords) say 'you talk and I'm going to ship you back to your country', so a lot of them accept the conditions that they live in," said Deros.

Mould growing on furniture in Malik Ali's apartment. (CBC)Deros said problems like this are not uncommon but insists the city can only intervene when tenants complain. She said she would try to help all the tenants in Ali's building find social housing nearby.

Andre Trépanier, who works for a community group in Park Extension, said he's been working to help Ali and insists the city needs to do something about landlords like Di Giambattista.

"It's a kind of owner that exists in Montreal that (doesn't) take care of their building. Sometimes it's not so bad but in this situation it's dangerous for the health of the (people) living there," said Trépanier.