The bow-legged leader of a gang of armed robbers who raided jewellery shops in Brighton and West Sussex was caught by police due to his bandy walk.

John Saunders and his gang specialised in stealing Rolex watches and netted £700,000 from jewellery shops in the South of England before they were snared by a police surveillance operation.

Yesterday the Old Bailey heard how Saunders was betrayed by his bow-legged gait as he was convicted of conspiracy to rob and a firearms offence.

He was caught out when security film of raids on jewellery shops clearly showed his distinctive bow legs.

Despite sometimes wearing two pairs of trousers, expert Dr Haydn Kelly said there was no doubt the gait of the robber on video matched Saunders' crooked walk.

Dr Kelly said only five per cent or less of the population had the same walk.

Edward Brown, prosecuting, said Saunders was the leader of the gang which had carried out robberies in Brighton, West Sussex, Reigate, Surrey and Knightsbridge in London, over an 18-month period.

They had been targeted by police who had watched them sizing up several shops.

The gang netted more than £100,000, including £52,000 worth of Rolex watches in a raid on Presley's Jewellers in Castle Square, Brighton.

They pressed a buzzer to get in and pulled on masks. An assistant ran out of the shop to raise the alarm despite being warned she would be shot.

However they were arrested in November last year after police marksmen shot out the tyres of a car in Kingston, Surrey.

In the boot of the Ford Fiesta they found a holdall containing a sawn-off shotgun and cartridges, a sledgehammer, changes of clothes, gloves and a mask.

Mr Brown said when 38-year-old Saunders, of Bierley, Bradford, was arrested he was wearing two pairs of trousers so he could quickly remove one pair and disguise himself after the robbery.

Saunders' nephew, Jamie Saunders, 19, of Sutton, Surrey, was convicted of conspiracy to rob and will be sentenced separately.

John Saunders, his brother James Roberts, and John Leghorn-Scott are expected to be sentenced for armed robbery in the next week.