A description of a gunman who subjected two Securicor staff to a terrifying hijacking before stealing £1 million has been released.

The Securicor workers, a man and a woman, were forced at gunpoint to follow a green Rover in their van for five miles during the hijack at 9am on Tuesday.

The van, which was targeted in Fitzalan Road, Roffey, near Horsham, was then stopped at a remote spot near the village of Faygate, where cash was unloaded into the S-reg Rover 216.

The gunman was today described as black, in his 20s, 6ft and well built. He was wearing a blue Securicor-type open-face helmet and a dark jacket with the word "security" in white across the back.

After transferring the cash, he and an accomplice who was driving the Rover sped away.

A Sussex Police spokesman said the amount stolen may have been "at least £1 million".

Securicor is offering a £100,000 reward for information.