The battalion is part of the Royal Regiment of Scotland

The soldiers from the Argyll and Sutherland Highlanders were tested after returning from a break in the Mexican resort of Cancun.

An Army spokeswoman said their Commanding Officer had applied for their discharge, which would happen in "the next few weeks".

Defence chiefs would not confirm those involved had taken Class A drugs.

The soldiers reportedly took heroin and cocaine.

An Army spokeswoman said drug taking of any kind was not tolerated in the armed forces .

A spokesman for the Ministry of Defence added: "Drug use is incompatible with life in the armed forces and is not tolerated.

"Positive test results in the Army over the past four years average around 0.7% compared with over 7% in civilian work place drug testing programmes."

The Argylls, the 5th Battalion of the Royal Regiment of Scotland, had been sent to Cancun after an exercise in the jungles of Belize lasting several weeks.