(CNN) -- A British aid worker who died during an operation to rescue her from kidnappers in Afghanistan may have been killed by a grenade thrown by American forces trying to free her, British Prime Minister David Cameron said Monday.
Gen. David Petraeus, the top U.S. commander in Afghanistan, has launched an investigation into the failed attempt to rescue Linda Norgrove, 36, Cameron said.
NATO and British officials had said earlier she was killed by her captors, who detonated an explosive.
But Cameron said on Monday that statements made about Norgrove's death over the weekend were "highly likely to have been incorrect," although they were made "in good faith".
Petraeus contacted him Monday morning, he said, with new information.
But Cameron said he could not make a firm statement about the cause of her death until the investigation was complete. It will be a joint investigation between the United States and United Kingdom, he said.
The British prime minister said he believed "profoundly" that it had been the right decision to try to rescue her, although he looked shaken at times during his statement to the press.
CNN
