UNITED NATIONS (AP) — The United Nations says "friendly fire" from Afghan security forces may have killed a U.N. employee during a Taliban attack in October on a guest house filled with U.N. staff.

U.N. spokesman Martin Nesirky said the preliminary conclusions of the U.N. mission in Afghanistan's investigation raised "the disturbing possibility" that an American U.N. staff member died from "friendly fire."

A high-level board of inquiry established in January is expected to submit a final report on the attack soon, he said.

Germany's Stern magazine reported on its Web site Friday that it obtained amateur video indicating that U.N. security guard Louis Maxwell, from Miami, was killed after he escaped from the guest house to the street — not from a terrorist bullet or explosives as the Afghan government claimed.