Rock group Kasabian said "they had no choice" but to ask singer Tom Meighan to leave the band after he was charged with domestic assault.
On Tuesday, the 39-year-old pleaded guilty at Leicester Magistrate's Court to assaulting his former fiancee Vikki Ager while drunk on 9 April.
A day earlier, the band said he had stepped down due to "personal issues".
But after the case, they confirmed they had severed all ties, saying: "domestic violence can never be excused".
"No-one in the band wanted this to happen," said a statement posted to Kasabian's social media accounts.
"We have all worked so hard together for the past 23 years and had big plans for our future together. We are completely heartbroken.
"But we were left with no choice but to ask Tom to leave the band. There is absolutely no way we can condone his assault conviction."
In court on Tuesday, Magistrates heard that Meighan pushed Ager over repeatedly, held her by the throat and threatened her with a wooden pallet during the assault on 9 April, 2020. Ager also hit her head on a hamster cage after being thrown across a room.
CCTV footage of the incident showed the singer dragging Ager by the ankles, leaving her with bruises to her knees, elbow, ankle and "a reddening around her neck".
A child witnessed the "sustained assault", the court was told, and contacted 999 to report that a "domestic incident was taking place".
Meighan, of Narborough, originally denied an assault had taken place, but after watching video footage of the incident he told police he could not watch it any further because it was "horrible".
The district judge, Nick Watson, told the singer: "I could have sent you to prison" but instead gave him an 18-month community order and told him to carry out 200 hours of unpaid work.
Meighan will also be required to complete five days of rehabilitation, and was ordered to pay a £90 victim surcharge and £85 in prosecution costs.
Now that the legal proceedings have been concluded, we can comment on the departure of Tom Meighan from the band. Full statement below. Kasabian x pic.twitter.com/vP7Y61sxQA— KasabianHQ (@KasabianHQ) July 7, 2020
Following the prosecution, Kasabian said they wanted to give fans a fuller explanation of his departure from the band.
"As soon as we found out about the charges made against Tom, we as a band made the decision that we could no longer work with him."
They added: "Ultimately, as much as Tom hurt us all, we're not the victims in all of this. Domestic violence is something that can never be excused."
Meighan was a founding member of the band in 1997 alongside guitarist Serge Pizzorno.
They went on to become one of England's biggest rock groups, with five of their six albums going to number one. They headlined the Glastonbury Festival in 2014 and won best British band at the 2010 Brit Awards.
Meighan's departure leaves guitarist Serge Pizzorno and bassist Chris Edwards as the only remaining founding members, alongside drummer Ian Matthews, who joined in 2004.
It is unclear whether they will continue as a trio, or hire a new singer to replace Meighan.