A purported Taliban (search) spokesman said Saturday that the group has killed a missing American commando, but he offered no proof and the U.S. military said it was still searching for the Navy SEAL.

The commando is the last of a four-member elite commando team missing since June 28 in Kunar (search), near the Pakistani border. One of the men was rescued and the other two were found dead.

"This morning in Shagal district in Kunar province, the Taliban killed the American soldier and cut his head off," Mullah Latif Hakimi, the purported spokesman, told The Associated Press in a telephone call. "We left the body on a mountainside in this area so Afghan or U.S. soldiers there can find it."

Hakimi repeatedly has said the rebels were holding the commando. But information from him in the past has frequently proven exaggerated or untrue, and his exact tie to the Taliban leadership cannot be independently verified.

U.S. military spokesman Lt. Col. Jerry O'Hara (search), however, said "the search for the commando continued.

"The only proof we have is that he is missing," he said. "We will run down these reports to see if anything pans out."

When asked for evidence, Hakimi said, "the proof will be when the Americans find his body."

Hakimi said earlier this week that the rebels would release a video, but he made no mention of that Saturday.

"We have extracted very useful information as he was an important person. He gave us details about the American military strategy, their bases and future military plans," he said, without elaborating.

The Navy SEAL team went missing after a special forces helicopter carrying reinforcements to the mountainous area was shot down, killing all 16 Americans on board, the deadliest single attack on the U.S. military since the war here began in 2001.

The 16 troops on the helicopter were responding to a call for help from the four SEAL commandos on reconnaissance in the rugged Afghan mountains who were attacked by militants.

Afghanistan has seen an unprecedented spate of insurgent fighting that has left about 700 people dead since March and threatened to sabotage three years of progress toward peace. Afghan officials insist the violence will not disrupt landmark legislative elections slated for September.