A missile was sent to Britain through ordinary post by military engineers in Afghanistan, triggering a full-scale alert.

The 70mm Flechette rocket travelled 3,500 miles from Afghanistan to an RAF base inside an ordinary package, The Sun reported Wednesday.

The package was opened at Wattisham Airfield, in Suffolk, where over 70 defence workers had to be evacuated after the missile was noticed.

The missile, which is used by Apache helicopter crews, is considered one of the most powerful rockets in the world.

The incident took place two years ago and came to light now after a Freedom of Information request.

Engineers servicing a gunship chopper at Camp Bastion declared its missile launcher broken. But they did not notice it had a missile in it, show the Ministry of Defence documents.

The weapon was then packaged and sent to Britain as a "non-dangerous" item.

An inquiry found it was a "wholly avoidable" incident.

"We have made every effort to address certain procedural shortfalls highlighted by the incident and there has been no repeat of the incident to date," a spokeswoman of the Ministry of Defence was quoted as saying.