Recalls how drummer Steven Adler's girlfriend, Adriana Smith had sex with Axl, who recorded it and used the sounds on track Rocket Queen

Canter tells of the wild years in the 1980s when the band came close to dying as they blew $35,000 on heroin

Movie is now planned about the band directed by James Franco

Band hammered out a big money deal with Duff as the middle man because he was speaking to both Slash and Axl - the band members at war

It was a spectacular and, for fans, long overdue reunion: Axl Rose, Slash and Duff McKagan on stage as Guns N' Roses for the first time in 23 years.

First came two warm-up gigs, then a full-scale performance at Coachella on Saturday night.

Now the full story of how one of rock's longest feuds was ended can be revealed as one of the band's closest friends tells Daily Mail Online the details of the peace deal which got them back on stage.

Marc Canter, Slash's best friend, has revealed how it was bassist Duff McKagan who hammered out a peace settlement - after Slash split from his wife.

Duff, he says, was the only person who spoke to both the warring ex-bandmates and could lead them to a peace settlement.

But he said one of the key elements fell into place after Slash split from his wife Perla Ferrar in 2014, 13 years after they married.

Reunited: Duff McKagan, Axl Rose and Slash on stage at Coachella as they reunited, with an injured Rose in a throne

Warring parties: Slash (left) and Axl Rose (right) were not on speaking terms, with it taking Duff McKagan to bring them back together

Split: The divorce of Slash and Perla Ferrer opened the way for the peace talks, revealed Marc Canter

Ferrar managed Slash's career and held executive posts in all of his companies, but the pair divorced in January last year.

Axl, he says, felt that Ferrar was 'controlling' and her presence was a key obstacle to any reunion.

'Perla was out of the picture and Axl didn't like Perla and the way she controls things,' Canter, 51, said.

It opened the way for McKagan to make peace.

Canter said: 'Duff was a big part in getting them back together. He was working with Axl again and is a good middle man. There was no-one else who communicated with Slash and Axl.

'When Axl was venting about Slash, Duff was able to help him see things through Slash's eyes.'

And Canter says that Duff has been instrumental in several business deals over the years.

'Axl put a live DVD out a couple of years ago that needed Slash's permission because it was the old songs,' he recalls.

'Before that Slash would never sign off and Axl would never sign off if Slash wanted music.

'Duff was somehow able to finagle Slash to sign off on that. Soon after that Axl signed off on one for Slash for Live at the Roxy. That was a sign of some kind of truce.

'So the the old partnership was working together but not talking. Then they started licensing music for movies because, before, they weren't doing that, because that requires all their signatures.'

For years a Guns N' Roses reunion had seemed extremely unlikely even to the band members.

'One of the two of us will die before a reunion,' Axl told Billboard in 2009.

For 15 years, he toured as the only original member of Guns N' Roses, releasing one album, 'Chinese Democracy,' in 2008.

Canter said he had hoped to be the one who finally brought the band back, but the book he wrote about the band's Sunset Strip early days, 'Reckless Road', put pay to that.

'I was the last middle man but I haven't been communicating with Axl - just Slash, Steven and Duff.

'Axl would get mad at me that I was defending Slash because he hated Slash at that time.

Lifelong friendship: Marc Canter, who runs his family's restaurant in Los Angeles, tells Daily Mail Online how he was disappointed not to help bring the band back together

Familiar setting: Duff McKagan, Izzy Stradlin, Axl Rose, Steven Adler and Slash in Canter's in 1985

'I always thought I would be the one to bridge that gap but I broke that bridge with Axl, he thought I'd betrayed him.

'And hearing things from Duff was a little bit different to hearing my opinion.'

Canter knew things were on the mend when Axl's close ally, Del James, wished Slash a belated happy birthday on Twitter on July 23 last year - something unthinkable unless Axl and Slash were reconciled.

Then in an interview with a Swedish outlet in August, Slash said he and Axl had buried the hatchet.

Canter said: 'I knew I could breathe and that something was in the works. Now there's nothing left for me to do - they're back together. I was trying to get them back together but now I don't have to do that. They're back.'

According to Canter, Slash and Axl's infamous bust up two decades ago was sparked when Axl knocked back a series of songs Slash had written for the group - so the guitarist moved his attentions to side project Slash's Snakebite.

Canter, who Duff has called him 'the sixth member of Guns 'N Roses' and was at the group's side as they recorded their record-breaking debut album Appetite for Destruction, revealed: 'Slash and Axl reached a point where they wanted different things. They were not on the same page as they were the years before that.

'Slash and Duff went off and wrote 12 songs and gave the tape to Axl and he said he would only record three or four of them.

'So Slash said: "Screw you." And he went off and did his side project.

'When he came back from that tour Axl had put his childhood friend Paul Huge in the band which Slash didn't want. They were at each others throats and needed a break. Then it dragged out.'

Speaking of the band's wild early days in the 1980s, Canter told how he watched the band nearly die as they blew their $35,000 advance from Geffen Records on heroin while recording 1987's Appetite for Destruction.

'They got put up in an apartment building and trashed that,' he said.

Appetite for destruction: The band in the early days, with Marc Canter joining the fun (second from left) - but with the signs of difficulty to come in the form of an open bottle at the front

Early years: A treasured photo Marc Canter took of Slash in his mom's basement

Debut: The band on stage at the Troubadour in June 1985

'The neighbors wanted them out of there and they were bingeing on bad drugs. Heroin is a bad drug. They were out of control.

'They ended up out of money with no new songs coming and the record company were ready to cut them. They were either going to die, go to jail, get dropped or all of the above.

'I wouldn't give them money anymore because they were doing bad drugs that I don't support. I wouldn't even give them food because then if I fed them they spend their money on drugs.

'They would go to the Seventh Veil strip joint and have sex with the girls - and strippers always had money.'

Canter, the third generation owner of famed Canter's Deli in Los Angeles, met Slash - real name Saul Hudson - at high school and they became firm friends.

He would give the band free food at Canter's, then run by his father, before they had any cash and even used his earnings from working at the deli to pay for adverts in the local music press promoting their gigs.

Canter has fond memories of those early days.

He recalls the now infamous story of how Axl had sex with drummer Steven Adler's girlfriend Adriana Smith in a New York recording studio and recorded it and put the sex noises on the track Rocket Queen.

He said: 'Adriana was a stripper, Slash's drinking buddy and Steven's girlfriend. She went with Slash, Axl and [manager] Alan Niven to New York to master the record. Steven did not go on that trip.

Notorious track: Guns N' Roses perform Rocket Queen live in September 1985. The track featured the sound of Axl having sex with Alicia Smith, drummer Steven Adler's girlfriend. 'She took one for the band,' says Canter

Wild years: 'They ended up out of money with no new songs coming and the record company were ready to cut them. They were either going to die, go to jail, get dropped or all of the above,' says Canter

'Axl kept saying he wanted to record a sex thing with his girlfriend Erin but she wouldn't do it. She knew it was for the band but didn't want to do it without Steven's knowledge.

'Alan Niven could see she was on the fence so came with a big bottle of Jack Daniels and put it on the table said: "How about for this for you and Slash." And she said: "Alright, I'll do it."

'Afterwards she felt guilty and it caused a little bit of trouble between Axl and Steven. If you ask Steven now he would deny it and say it was all about the rock and roll - but the truth is he was a little hurt.

'But it's not like they went to the movies together and then had sex. She did it for the band. Took one for the team.'

Now reunited, the band - featuring original members Slash, 50, Duff, 52 and singer Axl Rose, 54 - are refusing to talk to the press about their comeback.

Following their headline slot at Coachella the group will embark on their Not In This Lifetime North America tour.

A biographical Hollywood movie is also in the pipeline; James Franco will be directing the film.

Canter says Reckless Road, his 2010 book documenting the band's early days, has been optioned by Rise of the Planet of the Apes star Franco, 37, who plans to turn it into a blockbuster.