Max George says The Wanted's "personal lives" caused them to break up.
The group announced on Wednesday that they will split following their upcoming US tour, and the singer has revealed there was "a lot of tension" in the band recently.
Speaking to The Sun on Sunday newspaper, he said: "Over the past year there has been a lot of tension. Our personal lives drove us apart - things started to happen and we were drifting."
"We used to be such a brotherly pact, but it started to feel like it wasn't The Wanted any more."
Max admitted the moment he "started drifting from" the rest of the group was when his engagement to Michelle Keegan, which ended in 2012.
He added: "Some of the lads started getting settled - I got settled at one point.
"I started drifting from the band when I was in a long-term relationship."
However, his fellow singer Tom Parker has suggested the group started to struggle in the UK because of the time they spent trying to crack the market in the US.
He told the Daily Star Sunday newspaper: "I think we did spend too much time away from home.
"We were putting in the groundwork internationally but I think we were probably gone too long.
"It's hard to balance because you have to spend a lot of time in America if you want to crack it but you don't want your UK fan base to forget about you."
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