Indonesian divers in the Java Sea recovered the second part of the black box of the crashed AirAsia flight QZ8501 on Tuesday.

The discovery of the cockpit voice recorder comes a day after the flight data recorder was retrieved on Monday, the BBC reports.

The two devices will aid investigators in establishing what were the causes for the disappearance of the plane on 28 December 2014.

The AirAsia plane was conducting a flight from Surabaya to Singapore with 162 people on board when it disappeared from the radars above the Java Sea.

So far the bodies of 48 passengers have been recovered, but the majority of the victims are believed to be still contained in the fuselage.

An official of Indonesia's search and rescue agency said that the fuselage has been located about 1.5 kilometres from the place where the tail was found last week, but so far there were no plans on its recovery.

The voice recorder, which records all conversations between the pilots, was retrieved under the wreckage of a wing.

The causes of the crash still remain unknown, but bad weather is the most probable reason, as the last communication with the flight was a request of the pilot to change course to avoid a storm.

It also emerged that the company did not have a permission to fly the route on the particular day it disappeared, the BBC reminds.