In a stunt seemingly more reminiscent of Hollywood films, a teenage criminal in Britain has escaped from jail after posing as his identical twin brother, according to authorities.

Police have launched a hunt for 17-year-old Gary O'Donnell, who was serving a four-and-a-half year sentence for assault at Polmont Young Offenders' Institution in Stirlingshire, central Scotland.

It is believed the teenager got away earlier that morning after posing as his identical twin John, who was due for release from the same cell block after serving a 60-day sentence for motoring offences.

Gary presented himself when his brother's name was called and officers, none the wiser, let him go.