A confidential military report made public on Monday charges Iran offered protection to an Afghan insurgent leader who claimed responsibility for an August ambush that killed 10 French soldiers.
The report by Spain's CIFAS military intelligence agency, which was obtained by Cadena Ser radio and posted on the station's website, said Gulbuddin Hekmatyar enjoyed "total freedom" when he lived at a Tehran hotel in 2005 - with his security provided by the Iranian government.
He met daily with many unidentified individuals while in Tehran, added the report which was dated August 9, 2005, according to Cadena Ser.
Hekmatyar, who briefly served as prime minister during Afghanistan's civil war in the 1990s, is considered one of the country's most radical warlords who is already known to have sought refuge in Iran between 1996 and 2002.
The United States has offered a multi-million-dollar reward for his capture.
Last week, he said in a video message that his faction had carried out an ambush on August 18 that killed 10 French soldiers in Sarabi, to the east of the Afghan capital Kabul.
The incident, in which 21 troops were also wounded, was the deadliest ground attack on international troops since their 2001 dispatchment to Afghanistan to oust the hard-line Taliban regime.
Cadena Ser did not say how it obtained the report, which apparently was marked confidential and bore the seal of Spain's defence ministry. The radio station also said the intelligence agency suspects Tehran supplied an allied terrorist group with US-made Stinger missile launchers. Another report claims Iranian agents in April 2005 bought "several Stinger missile systems" from an Afghan arms dealer, Cadena Ser said.