Scientists have questioned the quality of raw data released by British satellite company Inmarsat that was used to determine Malaysia Airlines flight MH370 crashed into the Indian Ocean.
They said the information was insufficient to plot its course.
The London-based firm released a 47-page report yesterday detailing data communication logs recorded by the satellite operator, 10 weeks after the plane vanished on the way from Kuala Lumpur to Beijing with 239 passengers and crew on board. The Doppler effect, changes in the frequency of waves from a moving object, was used to deduce the flight path from the data.
But Steve Wang, spokesman for a support group for relatives of the 154 missing Chinese passengers on board, said: "The data they have is only separated data - how could it precisely define the track of the plane? I don't think the Malaysia side is really honest about all the data they have."
Relatives of those on board the Boeing 777 when it vanished want to draft in independent experts to recreate information and determine the plane's course.
Watch: What we know about Malaysia Airlines flight MH370
Dr Li Min, a researcher at Wuhan University, said the data was insufficient and could not be used to determine the plane's route or last known position.
"With such data, we can only calculate the distance between the plane and satellite. It is a relative position, which means, in theory, the plane could be anywhere on a large sphere around the satellite," he said.
Inmarsat and Malaysia's Department of Civil Aviation have also been accused of putting on a political show to coincide with Malaysian Prime Minister Najib Razak's visit to Beijing.
Jiang Hui, a member of the family aid group, said: "Personally, I think the data might be helpful … [and] could become key evidence that the Malaysia side had lied."
Inmarsat admitted the data it had released had been simplified and that it had published parts that were "important". Mark Dickinson, Inmarsat's chief engineer, told a US television interviewer the data could not in itself be used to recreate Inmarsat's work, but only to make a judgment about its findings.
"What's more pertinent is to see the messages and the important bits of information … and some explanation behind how the numbers are used," Dickinson said. He said it required a lot of engineering expertise "from different fields".
Professor Zheng Zhengqi, who studied satellite communication at the School of Information Science and Technology in East China Normal University, said the search for flight MH370 might have stretched the capability of Inmarsat and its satellites.
However, one former staunch critic of the Inmarsat data, Duncan Steel, a physicist and visiting scientist at Nasa's Ames Research Centre in California, posted on his blog: "The data now made available appear to make sense."
The Australian Transport Safety Bureau said the final attempted contact from the satellite to plane, which was partially successful, suggested an interruption to the electricity supply caused by fuel exhaustion.
The airliner disappeared on March 8. It is thought to have crashed in the Indian Ocean, off western Australia, but an extensive search has found nothing.