Boeing last night denied reports that its Shenzhen-based field service representative Robert Lowry had access to the wreckage.
A spokesman said: 'He may be helping, but he has not been to the site of the wreckage or got his hands on the wreckage.' He said Boeing headquarters in Seattle had received no official correspondence from Chinese authorities regarding assistance.
As soon as the accident was reported, the company prepared a team of technical personnel to send to the scene. They had been on standby since Friday, he said.
The spokesman could not comment on claims that the crash stemmed from an engine fault.
Some newspapers have reported the arrest of an engineer for saying the plane could fly when he was aware of a problem.
Meanwhile, Shenzhen mortuary officers said some of the passengers who perished in Thursday's air crash in the Special Economic Zone might be too badly burned for identification.