The US Navy has launched a probe against American sailors based in Japan for the alleged use and distribution of drugs, a spokesman for the US Seventh Fleet has confimed.

“The Navy has zero tolerance for drug abuse and takes all allegations involving misconduct of our sailors, Navy civilians and family members very seriously,” Commander Clay Doss, public affairs officer for the Seventh Fleet, told CNN on Sunday.

“These allegations are still under investigation and it would be inappropriate to comment further.”

News of the investigation by the Naval Criminal Investigative Service (NCIS) was first reported by the Wall Street Journal on Friday.

The daily said the drugs involved included LSD and ecstasy, among others, and that at least a dozen US Navy personnel were under suspicion.

The report said some of those being investigated were serving aboard the aircraft carrier USS Ronald Reagan as well as on shore in Japan.

Suspicions that drugs had been sold to Japanese residents means that Japanese authorities were also investigating, it added.

The Reagan, based in Yokosuka near Tokyo, is the only one of the US Navy’s 11 aircraft carriers homeported outside of the US, reports CNN.

If the drug allegations prove true, it would be the latest in a string of bruising black eyes for the Seventh Fleet, which has seen two of its guided-missile destroyers involved in deadly collisions with cargo vessels in the past year, reports of exhausted crews plagued by poor morale, and dozens of its former officers entangled in a Pacific-wide corruption scandal.