The producer of ITV1's Midsomer Murders has been suspended after saying the drama "wouldn't work" if there was racial diversity in the show.
Brian True-May, who co-created the series, told the Radio Times the long-running drama was a "last bastion of Englishness" and should stay that way.
Production company All3Media told the BBC Mr True-May had been suspended pending an internal investigation.
ITV said it was "shocked and appalled" by the producer's comments.
"We are in urgent discussions with All3Media...who have informed us that they have launched an immediate investigation into the matter," a spokesman added.
Mr True-May told the magazine: "We are a cosmopolitan society in this country, but if you watch Midsomer you wouldn't think so.
"I've never been picked up on that, but quite honestly I wouldn't want to change it," he said.
Of his all-white portrayal of rural life in Britain's murder capital he said: "Maybe I'm not politically correct."
The programme - which has run for 14 series - appealed to a "certain audience", he said.
Mr True-May added: "We just don't have ethnic minorities involved. Because it wouldn't be the English village with them. It just wouldn't work."
Asked why "Englishness" could not include other races who are well represented in modern society, he said: "Well, it should do, and maybe I'm not politically correct.
"I'm trying to make something that appeals to a certain audience, which seems to succeed. And I don't want to change it."
A study in 2006 found the programme to be "strikingly unpopular" with viewers from ethnic minorities.
Speaking to the BBC's Colin Paterson at the Royal Television Society Awards, Downton Abbey creator Julian Fellowes said he did not agree with Mr True-May's "sentiments".
"I think it's not true - I live in the country in Dorset and in Dorchester there is quite a variegated population, so it's not my observation," he said.
However he said he had never faced pressure to include any ethnic characters in his drama series.
Speaking to Radio 4's Today, Guardian columnist Simon Jenkins said he did not see a problem as the setting for the show was an "old-fashioned English village" and such villages were not known for their multi-ethnicity.
"The definition of old fashioned English village here I'm afraid, doesn't include multi-ethnicity," he said.
However Ash Atalla, producer of sitcoms The Office and the IT crowd, said it was a "generational thing", where people of a certain age liked to believe that "Englishness" was all-white.
"Midsomer Murders is not for someone like me. I'm too young and I find the show rather dull," he said.
"We have to be careful about seeking out something that offends us and then complaining. I would not want the viewers of Midsomer Murders complaining about something I liked."
He later told 5 live: "Interestingly the show's been going for years and years, there hasn't been a black actor and nobody's batted an eyelid until the co-creator himself pointed it out to the world."
Midsomer Murders, based on the books by Caroline Graham, was launched in 1997 and has featured 251 deaths, 222 of which were murders.
The producer has banned swearing, violence and sex scenes from the show but has tackled diversity issues other than ethnicity.
"If it's incest, blackmail, lesbianism, homosexuality... terrific, put it in, because people can believe that people can murder for any of those reasons," he told Radio Times.
Actor Jason Hughes, who has played the programme's DS Jones, said he had pondered why Midsomer continued to have no ethnic minorities.
"I've wondered that myself and I don't know," he said.
"This isn't an urban drama and it isn't about multiculturalism. That's not to say that there isn't a place for multiculturalism in the show. But that's really not up to me to decide.
"I don't think that we would all suddenly go, 'a black gardener in Midsomer? You can't have that'. I think we'd all go, 'great, fantastic'."
Actor John Nettles's final appearance on the drama was watched by an average of 7.1 million viewers last month.
The 67-year-old bowed out of the series after 14 years playing DCI Tom Barnaby.
Actor Neil Dudgeon will replace the central character as DCI John Barnaby, Tom's cousin, when the series returns to TV screens next week.