The pacifist singer was so incensed about the British army's killing of 13 unarmed demonstrators in Derry in 1972 that he agreed to hold talks with an IRA representative in New York shortly afterwards. But such was Lennon's confused thinking about Ireland that during his talks with a leading Belfast Provo he also suggested doing a gig for working-class Northern Ireland Protestants.

Lennon's relationship with the IRA is confirmed by the Provos' former 'Belfast Brigade' press officer, Gerry O'Hare, in an interview with rock n'roll biographer Johnny Rogan. O'Hare, who later left the Provisional IRA and pursued a career in Irish journalism, said the Provos' high command sent him over to New York on a speaking tour shortly after Bloody Sunday. Through republican contact in the city, O'Hare linked up with Lennon.

'You see in New York there were Irish Americans who kept him [Lennon] briefed. I was over on a speaking tour and a guy said to me, "would you like to meet John Lennon?" Within two days I was in his presence,' O'Hare said.

Lennon had recorded political agitprop songs such as 'Sunday Bloody Sunday' and 'Luck Of The Irish', donated royalties to the Civil Rights Movement and had joined anti-internment marches the previous year. O'Hare, who in the early Seventies operated under the nom de guerre of 'S O'Neil', said the IRA leadership regarded Lennon as a useful ally.

'He was taken very seriously because he offered to do two concerts - one in Dublin and one in Belfast. When I was in New York I met him briefly through a contact whose name I do not want to divulge. I went up to the apartment and I asked Lennon was he serious about all this. He said he was, but his problem was that if he left America he might not be able to get back in again and he was frightened about this.

'So I came back and told the people on our side, "he wants to do it, but this is his big problem." And then, of course, it faded from our priorities. But I did speak to him myself. He knew who I was and where I was coming from. He said he'd do it all right.'

O'Hare tells Rogan he was convinced that Lennon was dedicated to the Irish republican cause even if he appeared confused about the conflict.

'You have to think of the time. There was nobody bigger than the Beatles, and John Lennon was espousing his working-class values. We [the IRA] were thinking, "This is brilliant, how did he get away with it?"... Whether he [Lennon] was [just] caught up in the emotion, I don't know."

'He gave me the impression he was genuine. I said, "that's fine".' The upshot of it was that he said he would love to do a concert, but if he did it he insisted on doing one in Belfast too. I got the impression that he was very anxious to do one for the Protestant community as well.

'In the end he just explained to me, "I have a difficulty, my lawyers are fighting this. There's a lot of things I want to do and I badly want to go back home".' He kept saying "back home" and I presumed he meant London or Liverpool or whatever. Finally, he said, "until such time as that, this will have to be put on the long finger." So it was left to the guy who introduced me to him, that if it were ever going to happen then he would be the contact and we would do what we had to do on this side. But nothing ever happened.'

Rogan has also uncovered still classified FBI files on Lennon, which, he claims confirms MI5 whistleblower David Shayler's allegation that the British security services spied on Lennon because of the star's support for Irish republicanism.

· 'Lennon: The Albums' by Johnny Rogan is published next month by Calidore-Music Sales; £12.99.