Michael Costello has offered an apology to singer Leona Lewis after she claimed she was once dropped from a fashion show due to her size.
Earlier this week, the US designer accused US model Chrissy Teigen of bullying and making him feel suicidal.
Lewis called Costello's accusations "the pot calling the kettle black" and said she was left "embarrassed" by an encounter with him in 2014.
Costello said he had tried to contact Lewis and "wanted to apologise".
But, he told the BBC, he would have been willing to make a custom dress for Lewis "without a doubt", but he was not able to because he had only had seven days notice about the fashion show and was away from his Los Angeles base preparing for New York Fashion Week.
Lewis recounted an occasion in 2014 where, she claims, she was asked to fly to the US to wear one of Costello's dresses, but said she was then dropped from a charity fashion show after the sample size dress did not fit her.
The 36-year-old said the encounter had left her feeling "embarrassed" and "deeply hurt".
"Because I didn't look like a model size, I was not permitted to walk in his dress," she claimed. "I had to sit in the audience and was asked by press why I didn't walk in the show. I remember having to come up with excuses as I was so humiliated by it all."
She added: "I was left with deep insecurities after this and I've had to work hard over the years to love my body. I know that his designs are catered to women of all sizes now, and I'm glad he saw the light over the years."