Afghan officials say they've got video of a man overseeing the torture of Afghan civilians. Exactly who ordered the man to torture is a matter of fierce dispute – and also helps explain this year's erosion of trust between Washington and Kabul.

Allegedly, there's a videotape in Afghan government hands showing a man named Zakaria Kandahari presiding over the torture of an Afghan civilian who, along with 15 others, recently disappeared from Wardak Province. According to the New York Times, Kandahari, an American citizen, is "seen conducting" the torture session and "supervising" others.

But there is great disagreement over who Kandahari actually is. The Afghans say that Kandahari leads a U.S. Army Special Forces unit recently kicked out of Wardak over allegations of torture, disappearances and executions. The U.S. military command says unequivocally that Kandhari was an interpreter for the unit, not a leader; that he's not actually an American; and that the unit was not involved in any torture.

The video is only one component of the evidence Afghans told the paper they've compiled against Kandahari and the Special Forces A-Team that was in Wardak's Nerkh District. A 16-year old named Hikmatullah said Kandahari picked him up on incorrect suspicion of being an insurgent. "Mr. Kandahari beat and kicked him until his shoulder was dislocated. He was released after three days, he said," the paper reports, "but his brothers are missing."

The suspicion helps explain why President Hamid Karzai abruptly called in February for U.S. special operators to leave Wardak Province. It took only a few weeks for Karzai, the recipient of CIA money, to soften his position: the elite troops immediately left Nerkh, but they're still working out a timetable with the Afghan government to vacate Wardak entirely.

Kandahari's story is as wild as it is disputed. The A-Team, a detachment of 12 soldiers, moved to Nerkh from Kandahar, onto a base formerly used by Taliban leader Mullah Omar. Along with other soldiers in the unit, Kandahari wore a long beard and was seen riding "motorized four-wheeled bikes on hunts for insurgents." When the Afghans came to arrest Kandahari on murder and torture charges, Kandahari – apparently in his late 20s or early 30s with a big tattoo of a green sword on his upper arm – Kandahari split. Afghans thought the U.S. was protecting Kandahari; the U.S. denies it.

In fact, the U.S. is denying any involvement in disappearances and torture of Afghan civilians. "After thorough investigation, there was no credible evidence to substantiate misconduct by U.S. or ISAF forces relating to the detainees or deaths in Nerkh," the International Security Assistance Force, NATO's military command in Afghanistan, said in a statement. ISAF has apparently known about the video for months, Stars & Stripes reports, and has examined "a video of a detainee being 'assaulted' by an Afghan man, who worked as an interpreter for U.S. forces in the area." It's unclear if these videos are one and the same.

Without claiming to settle this dispute, two things remain true. First, Afghans have made wildly inaccurate claims about U.S. troops in the past: Karzai has even said they collaborate with the Taliban to dominate Afghanistan. Second, U.S. special operations forces have been accused of torturing Afghans before, in a constellation of transitory jails.

However the Kandahari mystery unfolds, it's unfolding at an inauspicious time. U.S. and Afghan diplomats are quietly negotiating an enduring post-2014 presence for U.S. troops, reportedly including some nine bases. The last thing those negotiations need is an obstacle in the form of U.S. complicity in torture, disappearances and murder.