A jeweller saved from a gunman's bullet by his mobile phone was hit by a modified blank, it was learned last night.

Darren Prior walked away unscathed when the bullet penetrated his jacket but bounced off the battery of his flip-phone.

A fingertip search of the shooting site revealed one of the two bullets used and it was sent for analysis.

Ballistics experts told detectives that while the gun used was real, the shell was a modified 9mm blank cartridge.

Detective Inspector Jo Wainwright, investigating, said the shell would have caused serious injury had it not hit the mobile.

"Fortunately, because it was a modified blank it did not have the same velocity.

"A real bullet would have gone through the phone and caused serious injury."

Experts believe the gun owner had no ammunition for the weapon and instead crafted shells from blanks.

Cards and messages congratulating Mr Prior for his have-a-go bravery have poured into the shop where he works.

His boss said: "The response has been absolutely fantastic."

Mr Prior, 23, was lucky to survive when the 6ft hooded gunman fired two shots as he ran from the Amore Jeweller premises in the Piries Place shopping precinct in Horsham.

Shoppers dived for cover as the offender, caught on CCTV waving a handgun, opened fire. He had demanded staff at Amore handed over jewellery.

He grabbed items worth thousands of pounds as he fled the store, hotly pursued by manager Mr Prior.

The offender was running along nearby Pump Alley when he stopped, turned and aimed his gun at Mr Prior.

One shot missed him by inches but the second struck him in the chest.

The robber, who was black and wearing a black hooded top, escaped. Mr Prior, badly shaken, was back at work in the shop on Monday and counting his lucky stars.

He told The Argus yesterday: "I'm feeling much better thanks."

The shop's managing director Lee Lawson said: "Darren has had cards and we have had customers and other retailers coming in and offering their support.

"Darren has been touched but he's trying now to get his life back to normal."

The case is being treated as a case of attempted murder.

Witnesses to the robbery on Thursday last week or anyone with information should call 0845 6070999.