Lao Airlines on Saturday said it had identified almost half of the 32 bodies so far recovered after a plane carrying dozens of people, many of them foreign travellers, plunged into the Mekong River.

In the country's deadliest known air disaster, all those on board died when the Lao Airlines turboprop ATR-72 plunged into the swollen waters in stormy weather on Wednesday near Pakse airport in Champasak province.

More than half of the 49 passengers and crew were foreigners from 10 countries.

Lao Airlines said that its team, in cooperation with Thai rescuers, investigators from the French-Italian aircraft manufacturer and local authorities, had identified 14 of the 32 bodies found so far.

Two Australian passengers, the Cambodian captain and several members of the crew were among those named so far.

"Our thoughts and prayers are with the families affected by this terrible tragedy," the carrier said in a statement.

Volunteers have battled strong currents in their search for bodies from the plane, most of which has sunk and is believed to have broken up.

In some cases, rescue teams have plucked the dead from turbulent waters many miles from the crash site.

A Chinese temple in Pakse has been turned into a makeshift autopsy centre, with experts flown in from around the world to help.

Jong-Pil Park, from South Korea's national forensic department, said the crash was a huge challenge for impoverished Laos, with the damage to the bodies creating further hurdles in identification.

"They need to analyse DNA samples, finger prints and dental (records). They need to solve by cooperating with many countries," he told AFP.

He said it could take up to two weeks to finish conducting the autopsies.

In an updated statement late Saturday, Lao Airlines said some of the bodies had been returned to their families, including the Cambodian pilot, whose body was flown back to Phnom Penh.

Families of those identified have already begun holding funerals for their loved ones.

"This is the biggest loss in my life," Souksamone Phommasone told AFP as he prepared to cremate his wife Chinda.

She died along with her mother and father as they returned in the ill-fated aircraft from a visit to see the couple's daughter in Vientiane.

Thailand has said the recovery operation is being led by local authorities with the support of its navy, air force and volunteer rescue teams.

Lao Airlines said the aircraft hit "extreme" bad weather while witnesses described seeing the plane buffeted by strong winds caused by tropical storm Nari.

According to an updated passenger list from the airline, there were 16 Laotians, seven French travellers, six Australians, five Thais, three South Koreans, three Vietnamese, and one national each from the United States, Malaysia, China and Taiwan.

Aircraft manufacturer ATR said the twin-engine turboprop aircraft was new and had been delivered in March.

Founded in 1976, Lao Airlines serves domestic airports and destinations in China, Thailand, Cambodia and Vietnam.

Impoverished Laos, a one-party communist state, has seen 29 fatal air accidents since the 1950s, according to the Aviation Safety Network (ASN).

ASN president Harro Ranter said investigators working to find a cause of the crash would look at weather forecasts given to the crew, indications on their radar and their own decision-making among other considerations.

"The investigation will show what caused the crash," he told AFP, adding that propeller planes like the one involved "are not less safe in poor weather conditions per se".

Laos was last audited by the United Nation's air safety arm, the International Civil Aviation Organisation, in 2010 and found to be just above world average for all factors except airworthiness and operations, which were just below.

Previously the country's worst air disaster was in 1954 when 47 people died in an Air Vietnam crash near Pakse, the organisation said.