A VIRGIN Australia flight from Melbourne to Sydney was forced to turn back to the airport ten minutes into the flight after cabin crew detected a "bad odour".

Virgin flight VA823 carrying 129 passengers made an emergency landing at Melbourne Tullamarine airport just before 9am (AEDT). It left the airport at 8.56am local time.

"There was an unusual odour in the cabin, not the cockpit," Virgin spokesperson Melissa Thomson told news.com.au.

"Purely as a precaution the pilot opted to returned to Melbourne as standard operating procedure."

The flight landed safely without incident and all passengers have been accommodated on later flights.

The plane is currently being inspected by Virgin engineers on the ground in Melbourne.

There are no details on what kind of smell was detected.

An airport spokeswoman said a full emergency procedure had been declared but the plane landed safely and the pilot required no further assistance.