A GRENADIER Guardsman who appeared to entertain tourists by pirouetting and performing silly walks while keeping guard outside ­Buckingham Palace is being investigated by the Army.

The unidentified soldier was filmed while on duty outside the Queen's official London home and the ­footage uploaded to the internet.

The soldier is seen in the clip, posted on YouTube last month, walking outside the Palace from his sentry box to a wall a short distance away.

As he marches up and down he stoops to pick ­something up, then on another patrol stops mid-stride with his foot in the air for a few seconds.

On another occasion the Guardsman performs a jaunty walk and later varies his speed and is also seen pirouetting three times before stopping outside his sentry box.