Mystery phone number could help solve the mystery of murdered London student Samuel Guidera

Exactly four years ago today Samuel Guidera was found collapsed in the street close to Penge East railway station. He had been stabbed in the heart and his wallet had been stolen. He died later in hospital.

The 24-year-old had spent the day watching football with friends before catching the train back from Bickley to Penge East, arriving just after 9.30 in the evening.

He crossed the footbridge over the railway to the Newlands Park exit.

Today, the detective leading the investigation revealed for the first time a mystery telephone number that was dialled from Samuel's phone moments before he was murdered.

The number, 0740 4776433 belongs to Lyca Mobile and is a Pay-As-You-Go Sim card which has never been activated.

Detective Chief Inspector Chris Jones believes Samuel's killer may have got his attention on the pretext he wanted to use his mobile phone.

Previously, Samuel's mother and father, Sarah and Chris Guidera, said:

In the four years since the murder detectives have followed and eliminated over a thousand leads, viewed and released hundreds of hours of CCTV and have spoken to nearly 900 witnesses.

They hope today's renewed appeal will reveal the information they desperately need to track down the person who stabbed the history and politics student on February 12th four years ago.

The CCTV footage below shows Samuel in a shop shortly after leaving Penge East Station.