The search for AirAsia flight QZ8510 which crashed into the sea on Sunday is set to move underwater, with the arrival of specialist equipment.

A French crash investigation team will use sensitive acoustic detection devices to try locate the plane’s “black box” flight recorder.

The Airbus A320-200 was flying from Surabaya in Indonesia to Singapore with 162 people on board when it vanished.

No survivors have been found and the cause of the crash remains unknown.

So far only 10 bodies have been found and brought ashore, with the search operation repeatedly held up by bad weather and rough seas.

One person has been identified as passenger Hayati Lutfiah Hamid – her funeral was held in Surabaya on Sunday.

The plane is almost certainly at the bottom of the Java Sea – several pieces of debris have been recovered but despite a massive five-day search the fuselage is still missing. Officials say most of the passengers could still be inside.

The BBC’s Karishma Vaswani in Jakarta says the hope is that the French-led team will have better luck than existing searchers in locating the “pings” emitted by the so-called black box.

This will help them locate the plane and, once retrieved, try to find answers as to what happened to it.

The head of Indonesia’s search and rescue agency, Bambang Soelistyo, said on Friday that wreckage and bodies are spread over a 5km area of the Java Sea off Borneo.

The search was now focusing on an area of 1,575 nautical square miles of the Java Sea off Borneo, he told reporters.

“Divers are already on standby at the navy ship Banda Aceh to dive on that priority area to locate the body of the plane,” he said. “I hope we’ll get a significant result today.”

Journalists in Pangkalan Bun – the nearest town to the suspected crash site – were shown pictures on Friday of what officials said was part of a wing flap.

The official in charge of operations there, Supriyadi, said local fisherman were being encouraged to look out for wreckage.

‘Unbelievably steep climb’

There were 137 adult passengers, 17 children and one infant, along with two pilots and five crew, on the plane. The majority of those on board were Indonesians.

Some investigators are reported to believe that the plane may have gone into an aerodynamic stall as the pilot climbed steeply to avoid a storm.

Officials have said the plane was travelling at 32,000ft (9,750m) when it requested to climb to 38,000ft to avoid bad weather.

When air traffic controllers consented to allow it to climb to 34,000ft a few minutes later, they got no reply.

A source quoted by Reuters said that radar data appeared to show that the aircraft’s “unbelievably” steep climb may have been beyond the Airbus A320’s limits.

However, the unnamed source emphasised that more information was needed before a definitive conclusion could be reached.

AirAsia previously had an excellent safety record and there were no fatal accidents involving its aircraft.