More than half the UK's top 100 journalists went to private schools, a survey for an educational charity says.
David Dimbleby: one of an "elite" few to feature in both 1986 and 2006
The Sutton Trust, which helps youngsters from underprivileged homes, also said that more than half of those with degrees had been to Oxbridge.
The proportion privately educated had risen since 1986 from 49% to 54%.
High training costs and low starting pay meant people from privileged backgrounds might come to dominate the news media even more, it said.
The trust's research focused on the educational backgrounds of 100 leading national newspaper editors, columnists, broadcast editors and news presenters.
It looked at those in 2006 and those in comparable roles 20 years ago - so online journalists were excluded.
It found that 54% of the current crop had been to private schools, compared with about 7% of the total school population.
A further 33% went to grammar schools and just 14% to comprehensives - attended by about 90% of youngsters.
In 1986 only 49% of the top journalists were educated privately, with 44% at grammar schools and 6% at comprehensives.
Of the 81% of the 2006 cohort who had been to university, more than half were educated at Oxford or Cambridge and a third were Oxford graduates.
Those were smaller shares than in 1986, when 67% had been to Oxbridge and two-fifths to Oxford, though at that time a slightly smaller proportion (78%) were graduates.
The trust's report said: "A common perception among leading editors we spoke to is that the gap in ability between those from private schools and those from state schools has widened over the last few decades.
"Young, independently educated aspiring journalists, they argued, are just more confident, knowledgeable and self-sufficient at an earlier age than their state school counterparts."
Trust chairman Sir Peter Lampl said: "This is another example of the predominance of those who are privately educated in influential positions in society.
"It cannot be healthy for our media leaders to come mostly from backgrounds that are so different from the vast majority of the population."
Part of the wider solution was to open up independent day schools to all talented youngsters, not just those whose families could afford the fees, he said.
"We also need to address the under representation of state school students, particularly those from less privileged backgrounds, at our leading universities."
The research was led by the news editor of the Times Higher Education Supplement, Lee Elliot Major, who said informal recruitment procedures exacerbated the problem - though in the BBC procedures were far more formal so, as one journalist had said, "you can't circumvent the system now".
But he was unable to look at the backgrounds of a wider range of journalists.
"The vast majority of editors said they did not collect such information, and were unwilling to devote resources to surveying their staff," the report said.
"Likewise the BBC, a publicly funded body, said compiling such information would take up too much time and money."