Six soldiers from a Yorkshire regiment could be dismissed from the Army after testing positive for drugs.
Members of the 2nd Battalion the Yorkshire Regiment, who are based at Beachley Barracks, near Chepstow, south Wales, are being investigated.
The drugs involved and the rank of the soldiers have not been disclosed.
A spokesman for the Ministry of Defence said: "Drug misuse is incompatible with life in the armed forces and it will not be tolerated."
The spokesman also said anyone caught with drugs had to face the consequences and that often meant dismissal from the armed forces.
"I can confirm that six members of the 2nd Battalion the Yorkshire Regiment provided positive tests following a recent testing programme," said the spokesman.
"We treat drugs seriously and they will not be tolerated. We have a random drug testing policy and anyone caught with drugs has to face the consequences, and that often means dismissal from the armed forces."
The 2nd Battalion the Yorkshire Regiment is also known as The Green Howards and were deployed in the Balkans in 2006.