UPDATED 7.13PM: Recovery teams have found two big parts of AirAsia Flight 8501, which crashed into the sea last weekend with 162 people on board.

News of the discovery came after Indonesia's transport ministry said the plane had been flying on an unauthorised schedule when it crashed, and the airliner has now been suspended from flying the route from the city of Surabaya to Singapore.

The parts of the plane were found in the Java Sea off the island of Borneo late Friday night, raising hopes that the remaining bodies and the black boxes, crucial to determining the cause of the crash, will soon be located.

"With the discovery of an oil spill and two big parts of the aircraft, I can assure you these are the parts of the AirAsia plane we have been looking for," Indonesian search and rescue agency chief Bambang Soelistyo told reporters.

Recovery teams have found 30 bodies of those killed when the Airbus A320-200 went down early Sunday during a storm, and Soelistyo said they were now sending divers to the spot where plane parts had been found to try to recover the remaining bodies.

"The main focus today is to find and evacuate victims," he said.

The director general of air transport, Djoko Murjatmodjo, said AirAsia's permit to fly the route of Flight 8501 had been frozen because the plane had been on an unauthorised schedule.

A statement from transport ministry spokesman J.A. Barata said AirAsia had not been permitted to fly the Surabaya-Singapore route on Sundays and had not asked to change its schedule.

It was unclear how the airliner, which has yet to officially respond to the ministry's statement, had been able to fly without the necessary authorisation.

The plane was operated by AirAsia Indonesia, a unit of Malaysia-based AirAsia, which previously had a solid safety record.

Search official S.B. Supriyadi in Pangkalan Bun said their Saturday operation would also comb coastal areas to see if bodies had drifted to shore, while their ability to send divers down would depend on sea currents and waves.

Russia has sent in dozens of divers to help with the operations, as well as two planes, one amphibious, while French and Singaporean investigators are helping to locate the black boxes.

The United States, Australia, South Korea and Malaysia are among other countries helping in the search effort.

Soelistyo said the larger of the two objects found on Friday night was about 10 metres by five metres.

"As I speak we are lowering an ROV (remotely operated underwater vehicle) underwater to get an actual picture of the objects detected on the sea floor. All are at the depth of 30 metres," he said.

He added however that the strong current was making it difficult to operate the ROV.

Of the 162 passengers and crew on board, 155 were Indonesian, with three South Koreans, one Singaporean, one Malaysian, one Briton and a Frenchman - co-pilot Remi Plesel.