Indonesian investigators searching for black boxes in the crashed AirAsia plane have lifted the tail portion out of the Java Sea.

It was not immediately clear if the cockpit voice and flight data recorders were still inside the tail or have been detached when the Airbus A320 plummeted into the sea on December 28, killing all 162 people on board.

The tail was hoisted from a depth of about 30 metres using inflatable bags that were attached to the rear of the aircraft and a crane to lift it onto a rescue ship.

• AirAsia flight data ‘hard to comprehend’

Intermittent underwater ping-like sounds were picked up on Friday about a kilometre from where the tail was located, but it was unclear if they were coming from the recorders located in the back of the aircraft.

It was possible the signals were coming from another source.

No metal was detected at the ping location, and Nurcahyo Utomo, a National Commission for Transportation Safety investigator, said the sounds could not be confirmed.

The discovery of the tail on the ocean floor earlier this week was a major breakthrough in the slow-moving search that has been hampered by seasonal rains, choppy seas and blinding silt from river runoff.

Officials were hopeful the black boxes were still inside.

Four additional bodies were recovered Friday – two of them still strapped in their seats on the ocean floor – bringing the total to 48.

Officials hope many of the remaining corpses will be found inside the fuselage, which has not yet been located by divers.

Meanwhile, Transportation Minister Ignasius Jonan cracked down on five airlines on Friday, temporarily suspending 61 flights, because they were flying routes on days without permits.

Earlier, all AirAsia flights from Surabaya to Singapore, the path Flight 8501 was on when it went down on December 28, were suspended after it was discovered that the low-cost carrier was not authorised to fly on Sundays.

Transportation Minister Ignasius Jonan also sanctioned nine more officials for allowing the plane to fly without permits, bringing the total to 16.