He's opened up on his cancer struggle

The famous Irish band was founded in 1993 by Walsh, however, has been engulfed in a feud with them for over a decade.

However, he agreed to take part in the documentary, despite undergoing chemotherapy at the time.

It was just last year that the music manager revealed he had been diagnosed with waldenstrom macroglobulinemia and explained on Celebrity Big Brother that he had been recovering from the rare form of cancer.

The 72-year-old described it as a "reality check".

The on-show admission came when he was asked about his experience of lockdown to which he explained: “I was sick, and I think nobody knew I was sick. I had cancer, a mild version, a rare one, in my blood.

He added: “I didn’t even know I had it until I went to the hospital. They checked me and then they found it.”

Referring to the mental strain it cause him, he said: “It’s just up here, even when I go past a hospital I almost get sick. It’s all gone, I’m fine. It was just the shock of being sick and that word – nobody wants that word.

“I have it blocked out, a reality check. You see so many people sick and it’s terrible. In my world it was all about pop music and all that. I didn’t think of anybody getting sick or anything like that. And that was like, wow, reality check – you’re in the real world.”

As reported by the MailOnline, a source said that in the Boyzone documentary Walsh was "really ill at the time but made the effort to appear on the programme."

They added: "He was having chemo for his blood cancer, so wasn’t looking his best and it really took it out of him.

"You will see in the documentary that he complains he is tired, but when Louis makes a commitment he stands by it."

The three-part documentary sees Walsh make some bold statements about the band.

In the trailer he said: "I prefer ordinary people, because they work harder. And they do whatever you want at the start." He continued to take jibes at the band throughout the clip, showing no signs of the on-going feud coming to an end.

Ronan Keating explained: "We were a bunch of kids put together. We weren’t perfect, we weren’t polished."

Keating, whose decision to leave the band led to their breakup, said on Good Morning Britain: "When I watched it first, I was hurt, I was on the floor, I was a mess, I was an emotional mess. I watched it again, I guess I looked at it from a different point of view."