The writer and producer of the critically acclaimed movie, which is based on the relationship between his father, Frank 'Tony Lip' Vallelonga, and virtuoso jazz pianist Dr. Don Shirley, was at the centre of a storm after an offensive tweet he posted online containing anti-Muslim sentiments resurfaced.
On Thursday, January 10, he apologised to Muslim-American actor Ali, who plays Shirley, in a statement and promised to "do better in the future."
"I want to apologize. I spent my life trying to bring this story of overcoming differences and finding common ground to the screen, and I am incredibly sorry to everyone associated with 'Green Book'," Vallelonga told Entertainment Tonight. "I especially deeply apologize to the brilliant and kind Mahershala Ali, and all members of the Muslim faith, for the hurt I have caused."
"I am also sorry to my late father who changed so much from Dr. Shirley's friendship and I promise this lesson is not lost on me," he added.
In the offending tweet, Vallelonga agreed with then presidential candidate Donald Trump, who claimed to have seen people, who he suggested were Muslim, cheering when the World Trade Center towers collapsed during the 9/11 terror attack. The false claim was swiftly debunked, and no factual video evidence exists to support it.
"100 per cent correct," Vallelonga reportedly replied to Trump from his now deleted Twitter account. "Muslims in Jersey City cheering when towers went down. I saw it, as you did, possibly on local CBS news."
Vallelonga's misstep is the latest controversy to hit the Golden Globe-winning movie. On Wednesday the film's director, Peter Farrelly, was forced to apologise after an article from 1998 resurfaced revealing how the filmmaker used to flash his genitals at cast and crew members as a "prank".
"True. I was an idiot. I did this decades ago and I thought I was being funny and the truth is I'm embarrassed and it makes me cringe now," the director said in his statement. "I'm deeply sorry."