An Airbus investigator walks near part of the tail of the AirAsia QZ8501 passenger plane in Kumai Port, near Pangkalan Bun, Central Kalimantan January 12, 2015. [Photo/Agencies]

JAKARTA - The cockpit voice recorder of crashed AirAsia flight QZ8501 was retrieved on Tuesday from sea and was on board an Indonesian navy ship bound for capital Jakarta for analysis, local press reported.

The black box was freed from beneath the heavy ruins of a wing early in the morning from a depth of about 30 meters (98 feet), a day after the aircraft's flight data recorder was recovered, said Tonny Budiono, sea navigation director at the Transportation Ministry.

"Thank God," he said. "This is good news for investigators to reveal the cause of the plane crash."

The cockpit voice recorder has been on board an Indonesian navy ship bound for capital Jakarta for analysis, news channel MetroTV said.

Since it records in a two-hour loop, all discussions between the captain and co-pilot should be available.

The flight data recorder retrieved near the wrecked wing of the Airbus 320-200 on Monday morning has also been transported to the capital for investigation.

Investigators may need up to a month to get a complete reading of the data.

The AirAsia airliner carrying 162 people crashed into the Java Sea on Dec 28 in a flight from Indonesia's second-biggest city of Surabaya to Singapore.