Authorities investigating the fire aboard the Ethiopian Airlines 787 Dreamliner passenger jet at Heathrow airport are looking at the emergency transmitter as a potential cause of the blaze.
The fire caused extensive damage at the rear of the plane and led to the airport being closed for a short time.
Investigators with Britain's Air Accidents Investigations Branch (AAIB) were examining components in the upper rear part of the aircraft including the emergency locator transmitter made by US electronics company Honeywell.
Nathan Drevna, a spokesman for Honeywell, confirmed that it had joined the investigation.
"It's far too premature to speculate on the cause, or draw conclusions," he said.
According to Reuters, Honeywell said it had not had previous problems with the transmitter although the Federal Aviation Administration in the US said one transmitters had failed in tests in 2009 and it had advised the manufacturer to replace them.
Richard Aboulafia, an aviation consultant with the Virginia-based Teal Group, said: "Unless the company can say for sure that the incident is isolated to this particular aircraft, it's not welcome news.
"The one systematic problem to plague the Dreamliner is that so many of its technologies are new that it is very difficult for the regulators to fully grasp all the changes."