The spokesperson said that the recording device was being transported to Jakarta’s port. It was not immediately clear if it was the plane’s flight data recorder or the cockpit voice recorder that had been recovered.

The Boeing 737-500 plane with 62 people on board plunged into the Java Sea last Saturday, four minutes after taking off from Jakarta’s main airport.

Starting with just one plane in 2003, Indonesia’s Sriwijaya Air has become the country’s No.3 airline group, aided by its strategy of acquiring old planes at cheap prices and serving routes neglected by competitors.

The fleet of Sriwijaya and regional offshoot NAM Air is nearly 20 years old on average - nearly three times older than Lion Air group, according to website Planespotters.net.