Kray, who has been in prison for 31 years, is collaborating on several songs with the New York trio, although any releases may not bear the band's name.

"Reggie's providing the lyrics and they're providing the music," said Kray's wife Roberta.

Reggie the celebrity: Kray on TV in 1965

The band's singer Huey visited the surviving Kray twin in jail, prior to appearing at this summer's Reading Festival.

The star had flown in especially early for the audience with the real life criminal.

"Huey and I have become firm friends," Kray told a British music paper.

The singer has been a vocal supporter of the campaign to free Kray, even being spotted wearing a Free Reggie shirt.

He used his group's Reading gig to highlight Kray's incarceration for murder.

"He dedicated the John Gotti song, King Of New York, to me and changed the chorus to `Hey, Hey, free Reg Kray' - and got the crowd singing it," said Kray.

According to his wife, the former East End gangster has been writing lyrics for at least three years. "They tend to be about human emotions - love, hope, expectation."

Reggie Kray at his brother's funeral

"We haven't heard the music yet - they're still working on it," she said. "We hope the first single will be out in the New Year, probably February or March."

A release early next year would coincide with Kray's next parole hearing.

He was sentenced to life imprisonment in 1969, with the judge saying he should serve a minimum of 30 years.

The 65-year-old, along with his twin brother Ronnie, were major forces in London's underworld in the 1960s, often courted by showbiz stars.

Their extortion and protection rackets eventually led to murder, with Reggie Kray killing fellow gangland figure Jack "the Hat" McVitie.

Ronnie Kray died in Broadmoor top security hospital four years ago.