Murder squad detectives hope a Crimewatch television appeal will snare the killer of a self-made East Sussex businessman.

Officers want to trace a man seen buying cans of lager moments before Michael Willard was stabbed. They say he is a potentially vital witness.

Mr Willard, 63, died from the single wound to his back as he arrived at work in Caves Road, St Leonards, with about £1,000 in workers' wages.

The married father, of Harley Shute Road, St Leonards, managed to stagger back into his office at Target Scaffolding to dial 999 on January 10.

However, he died within an hour at the Conquest Hospital in Hastings, sparking a murder inquiry codenamed Operation Granary.

Detectives hope the Crimewatch appeal, coupled with a £10,000 reward, will prompt vital information. A date is being decided for the broadcast.

Anyone with information should call the incident room on 0845 6070999 or 0800 555111.