Police have raided two houses in Sydney, Australia, following suspected threats against a police station.

One house is the family home of Talal Alameddine who was detained in October over the terror-linked killing of a police worker outside a police station.

Mr Alameddine is accused of supplying the gun which Farhad Jabar, 15, used to murder police accountant Curtis Cheng.

Police said the searches were conducted under firearms legislation, but that no "items of interest" were found.

"Any threat to police officers or police premises is of major concern and taken extremely seriously, as demonstrated by the operation we undertook today," Assistant Commissioner Jenkins said in a statement on Wednesday., without giving further details.

"We will continue to take every precaution necessary to protect our officers and the safety of the wider community, and will respond swiftly to any specific threats that are received."

He said the raids were carried out by the Middle Eastern Organised Crime Squad and Tactical Operations Unit officers, along with local police and other specialist units.

Mr Cheng was shot dead outside his office in Parramatta on 2 October in what the authorities say was a terror-related attack.

Iran-born Jabar was shot dead by police at the scene.

In the wake of the shooting, a number of people, including Mr Alameddine were arrested during police raids on several properties.

Mr Alameddine was released but later re-arrested and charged.

Australia has stepped up counter-terrorism efforts in recent months in the face of what officials say is a growing security threat from radical Islamists.