The first book to reveal what the East End’s notorious Kray twins were like behind bars is published today (Monday) written by an ex-Fleet Street journalist who penetrated the gangland family’s inner circle.

Author Robin McGibbon was welcomed into the Krays’ ‘inner sanctum’ and saw the brothers at close quarters—Reggie in top-security prisons, his bisexual brother Ron in Broadmoor.

He had already ghost-written older brother Charlie Kray’s memoirs and was treated by the Kray clan as a trusted friend.

The Krays who were brought up in Bethnal Green were jailed in 1969 at the end of 20 years of gangland murder, extortion and protection racketeering.

McGibbon spoke to the twins on prison visits, on the phone and a series of letters while they were ‘inside’, advising on personal matters and negotiating media rights to Ronnie’s funeral.

He describes in his book, ‘The Krays: Their Life Behind Bars,’ the twins’ contrasting personalities with previously-unseen correspondence.

The letters show up the maddening mood swings and egomania of the aggressive Reggie and the old-fashioned courtesy and extraordinary generosity of his schizophrenic twin who revealed personal memories he had never shared with anyone but family.

McGibbon, a former national newspaper journalist who also ‘ghosted’ East End celebrity Barbara Windsor’s autobiography ‘All of Me’, has written a revealing narrative of the Krays, the ‘inside’ story of two underworld folk legends whose terrifying legacy continues to fascinate people today, including those who weren’t even born during their reign of terror of the 1950s and 60s.

‘The Krays: Their Life Behind Bars’, published by Great Northern Books today (Monday).