Most bodies recovered from a Cypriot plane that crashed near Athens with 121 people on board were frozen solid, a Greek official said, suggesting the airliner was a flying tomb before it plunged to earth.As accident investigators combed the crash site for clues, aviation experts were baffled at what appeared to have been a catastrophic failure of cabin pressure or oxygen supply in freezing temperatures at 35,000 feet—nearly 10 km up, higher than Mount Everest.One expert said reports of extreme cold suggested there was no air circulating in the cabin. ‘‘Autopsy on passengers so far shows the bodies were frozen solid, including some whose skin was charred by flames from the crash,’’ the Defence Ministry source, with access to the investigation, said on Monday.The Helios Boeing 737 was carrying 115 passengers and six crew members when it crashed 40 km north of Athens on Sunday. There were no survivors. Rescue workers recovered the body of the pilot, a German identified as Martin Hans Gurgen, and the plane’s black box flight recorders, which would be sent to France for analysis. The recovery of the black boxes is crucial to determining the cause of the worst air disaster in Greece. —Reuters