A pickpocket who turned himself into a "human deposit box" by stashing 53 stolen phones inside a swimming costume worn underneath his clothes at a Royal Blood gig has been jailed for three years.

Alin Marin wore the full-length compression suit to a concert by the band in Birmingham, where he swiped phones from crowd members in the mosh pit.

Shortly after leaving the gig at Arena Birmingham, the 22-year-old was arrested in nearby Broad Street and the stolen phones were found in a nearby car park.

Police said Marin turned himself into a 'human deposit box'. Credit: West Midlands Police

On Monday, Marin pleaded guilty to theft at Birmingham Crown Court and was jailed for three years.

Following reports of a high number of phone thefts at Royal Blood concerts during their 2017 tour, the band issued a plea to fans to take care of their valuables at the gigs.

In response to the reports, West Midlands Police carried out a "proactive" operation at the November 18 concerts and plain-clothed officers were in the crowd.

The stolen phones were recovered from a car park. Credit: West Midlands Police

Birmingham city centre Police Sergeant Julia Slater explained that many of the phones had been stolen from the front pockets of people's jeans - where they wrongly believe the mobile will be safer, "but due to the jostling in the mosh pit they simply didn’t realise they’d been targeted".

Sgt Slater continued that the swimming costume allowed Marin to "effectively turned himself into a deposit box for the phones, allowing him to carry tens of phones concealed around his body".

Alin Marin has been jailed for three years. Credit: West Midlands Police

People can record details of their phones and other valuables on the national property register at Immobilise, which can help police reunite stolen items with owners.