Some Afghan forces that are being trained by the US military to take over the mission by 2014 have been found dealing drugs to American soldiers, according to a report.

Judicial Watch, a conservative US watchdog group, found that that between January 2010 and December 2011, the Army investigated 56 soldiers in Afghanistan for the possession, use or distribution of opiates.

According to Fox News, a December 2011 report from Army Criminal Investigation Command showed that at one forward operation base the drugs hash, pot and heroin were purchased 'from various Afghan National Army and Afghan National Police personnel.'

In another case, an Afghan interpreter sold various opiates to soldiers, and other drugs were also available, the report said.

A CID report dated August 2010 showed a soldier admitted to buying the painkiller 'nalbin from a local national, while attempting to purchase steroids.'

Judicial Watch president Tom Fitton said that it's not clear from the documents whether the cases in Afghanistan are "isolated incidents" or symptoms of a more widespread drug problem.

According to Judicial Watch, the Army investigative reports show at least eight confirmed overdose deaths involving the drugs oxycodone, heroin and morphine.

In one death announcement, the watchdog noted that the Defense Department release described the manner of death as "non-combat related."

"We're obviously not interested in invading the privacy of those who died, or their families. But it looks like we can't find any public reporting about this," the report quoted Fitton, as saying.

Meanwhile, Judicial Watch has said that it is waiting for responses on drug use in Afghanistan from the Navy, Air Force and Marine Corps.