Indonesian divers on Sunday believed they found the black box of the AirAsia plane which crashed in the Java Sea a fortnight ago with 162 people aboard, the transport ministry said.

But they failed to retrieve it because it was stuck under debris from the main body of the plane, it added.

"The navy divers in Jadayat state boat have succeeded in finding a very important instrument, the black box of AirAsia QZ8501," said Tonny Budiono, a senior ministry official.