Investigators suspect that the co-pilot of the Malaysia Airlines Flight attempted to make a mid-flight call from his cellphone before the MH370 was diverted from its scheduled route, Malaysia's New Straits Times reported sources as saying on Saturday.
However, the call ended "because the aircraft was fast moving away from the (telecommunications) tower", a report said on Saturday citing unnamed investigators.
Another source told the Malaysian daily that while Fariq Abdul Hamid's "line was reattached", there was no certainty that a call was made from the Boeing 777 that vanished on March 8, Agence France-Presse reported.
Titled a "desperate call for help," the report did not divulge the contact details of the other person on the line.
After the Malaysian airliner mysteriously vanished en route from Kuala Lumpur to Beijing with 239 people on board, Fariq and Captain Zaharie Ahmad Shah have been subjected to intense scrutiny.
"Investigators last month indicated that the flight was deliberately diverted and its communication systems manually switched off as it was leaving Malaysian airspace, triggering a criminal investigation by police that has revealed little so far," AFP reported. "The fate of flight MH370 has been shrouded in mystery, with a number of theories put forward including a hijacking or terrorist attack and a pilot gone rogue."
Although previous reports in the Malaysian media hinted at calls made by the captain before or during the flight, they remained unconfirmed and were not released.
After turning off course, MH370 flew low enough near Penang island on Malaysia's west coast for a telecommunications tower to pick up the co-pilot's phone signal, the NST report said.
Between the time the plane veered off course and blipped off the radar, the phone line was "reattached," the government-controlled paper quoted the second source as saying.
"A 'reattachment' does not necessarily mean that a call was made. It can also be the result of the phone being switched on again."
Malaysia's transport ministry told AFP that it was examining the NST report and will issue a response.
The Malaysian government and media have repeatedly contradicted each other and themselves over details of the search and criminal investigation, AFP reported.
