The documentary film-maker Michael Moore is to join a growing boycott of next month’s Oscars following the announcement that no actors from black or ethnic minority backgrounds have been nominated for awards.

After the US Academy of Motion Picture Arts and Sciences’ failed to highlight the work of non-white professionals for the second year running, Jada Pinkett Smith and Spike Lee and other stars have announced they will not attend the 2016 ceremony.

Moore, an Oscar-winner in 2003 for his documentary Bowling for Columbine, told The Wrap that Hollywood’s struggles with diversity, and the ethnically limited film industry culture in Los Angeles, in particular, were to blame for this year’s all-white list of nominations. “A fish rots from the head down,” he said. “The problem has to get fixed in the studio system, which has been a white-dominated, male-dominated industry for ever.

“When you’re working in New York, you have a day-to-day existence with African Americans in the industry here,” added Moore. “But I can fly to LA for two or three days of meetings and never encounter an African American person in any position of power. I can very easily leave LAX, go to a West Hollywood hotel, have a meeting in Burbank, another meeting in Century City and another in Santa Monica, go back to LAX and never encounter an African American who isn’t in a service position. I love LA but the problem has to get fixed there.

Meanwhile, actor David Oyelowo has called for “radical and timely” reform of the Oscars within months, rather than years, after Academy of Motion Picture Arts and Sciences president Cheryl Boone Isaacs’ vowed to take “dramatic steps” to tackle a drastic escalation in the row over this year’s all-white list of nominees.

Selma star Oyelowo, who famously missed out on a best actor nomination for his role as Martin Luther King Jr at last year’s Oscars, said the current Academy “doesn’t reflect me, and it doesn’t reflect this nation”. He compared the battle over diversity at the world’s most famous film ceremony to the 1960s campaign for African American voting rights.

And Oscar nominee Mark Ruffalo has told Sky News he is “really sympathetic” to those who have criticised the Academy Awards for its lack of black stars in the top categories. He is nominated in the best supporting actor category for his role in Spotlight where he plays a journalist at a paper that discovered a cover-up of child sex abuse in the Catholic church in Massachusetts.

He is one of the first Oscar nominees to comment on the row.

Speaking at the film’s premiere in London, he said of the boycott call: “I do have a great deal of sympathy for it and I think it is a powerful gesture.

“And I think that those folks who are getting involved there should get involved with the people who are losing their lives every day, in the Black Lives Matter movement.”

He however said: “It’s something I am struggling with personally to get behind this or not.

“The only reason I am probably not going to take part in the boycott is because I am representing another kind of victim and the Oscars mean a lot to these people.”

Also Dustin Hoffman, who was in London for the National Television Awards, told Sky News there is “subliminal racism in the US”.

He added that he thought the killing of black people by police was also an important issue.