Gustav Reinop, 29, told the Estonian media he was a BBC reporter located near the Afghan capital of Kabul, but a mobile phone positioning system later placed the phone used during the interviews in Estonia.
The positioning system showed no rerouting services were used.
Viv Marsh, an editor for the BBC radio program "Europe Today," said the BBC currently has no reporters in Afghanistan, increasing the concerns circulating about the validity of Reinop's interviews.
Reinop spoke by mobile phone Oct. 12 with Radio Estonia, television channels ETV and TV3, the daily newspaper Eesti Paevaleht and business daily Aripaev.
As questions about the location of the interview mounted, Reinop could not be reached for comment. His mobile phone was switched off and the recorded message was in Estonian.
During one interview Eesti Paevaleht did ask Reinop how he thought the newspaper had been able to reach him by mobile phone in communications-challenged Afghanistan.
"It was a total surprise also to me," Reinop said.
Not only are mobile phone networks almost non-existent in Afghanistan, but Estonian mobile phone operator EMT - which provides the service for Reinop's phone - has no contract to provide a connection with any companies in the Afghan region.
In his interview with Radio Estonia, Reinop said he had arrived in Afghanistan via Moscow on board a Russian military aircraft Oct. 10. He said after landing in an unidentified location he was transferred to a U.S. military aircraft and flown to a temporary base about 50 kilometers from Kabul.
Reinop reported seeing thousands of U.S. Marines located at the base.