An Air India flight has made an unscheduled landing at Melbourne Airport after dumping fuel.

The Delhi-bound plane took off from Tullamarine Airport about 11.30am, an Air Services Australia spokeswoman said.

A flight radar showing the Air India flight path circling over Melbourne.

The pilots requested to return to the airport when the plane encountered a "minor technical issue" soon after departing, she said.

However, planes cannot land at the airport with a full tank of fuel, the spokeswoman said.

"In order for the aircraft to return, it needed to dump fuel," she said.

The plane flew over Port Phillip Bay where it dumped fuel, in accordance with routine procedure, before making its way back to Tullamarine.

"It was a normal approach and no emergency was declared," the spokeswoman said.