THERE was no immediate threat to passengers or visitors at Melbourne Airport after a suspicious package was discovered today, the Australian Federal Police said.

A parcel containing an unknown substance was located at the Australia Post outlet about 12.15pm, with AFP called in to assist.

MFB crews also arrived on the scene.

An AFP spokesman confirmed a package was found but has assured there was no danger to nearby visitors.

He said the package initially appeared to be a non-hazardous material and has been sent off for confirmation.

“At this stage, the matter is now finished,” the spokesman said.

Earlier the Australia Post mail centre facility at the airport has gone into lockdown after the package was found.

“A package containing an unknown substance was discovered and a request was made for AFP assistance,” an AFP spokeswoman said.

“The AFP would like to assure the general public that there is no immediate danger at the Melbourne Airport precinct.”

The alarm was raised after a worker at the Apac Drive facility in Tullamarine was believed to have discovered a suspicious yellow liquid contained in a package.

Workers who came into contact with the substance were initially put in isolation.

Flights from the airport were not affected.