In recent years the V&A has attracted record crowds to its exhibitions about musicians such as Pink Floyd and David Bowie, while the Tate Modern has staged hugely popular Picasso and Modigliani shows.

But a report by the London School of Economics warns that the trend of putting on safer exhibitions by established artists to guarantee high visitor numbers and offset a decline in state funding could make it even harder for experimental and minority artists to break through.

Artists including Grayson Perry and senior staff from the British Museum were among those surveyed for the study. Ernst Vegelin, the head of the Courtauld Gallery in London, told the researchers: “Museums are having to gravitate towards projects that are going to guarantee a return and which tend to build on pre-existing popularity, reducing the scope for encounters with unknown art forms.”

LSE researcher Kristina Kolbe said the shift to more populist shows could lead to even fewer opportunities for black and minority ethnic, disabled, LGBT and female artists.

Kolbe, co-author of the report, The Art World’s Response to the Challenge of Inequality, said austerity cuts had made public art institutions increasingly reliant on wealthy private collectors and mega-galleries for funds and loans of work to put on shows by major artists.

Museums and galleries worried this could compromise their civic values because private donors were often pushing work by artists they own or represent to increase their value, she added.

Kolbe compared this trend to insider trading. She said: “The super-rich often have the art to loan, or can support exhibitions but are also able to up the value of their own investments at the same time.”

The number of mega-galleries in Mayfair, such as the Gagosian and David Zwirner, which represent blue-chip artists, has grown in the past decade, while smaller galleries in east London and Fitzrovia, which represent emerging artists, have closed.

One of the most significant recent losses is the non-profit Parasol unit, which will close its gallery in Hoxton in late March. The foundation, established by Iranian-born curator Dr Ziba Ardalan, has shown many emerging international artists and recent UK art school graduates.

Ardalan said the increasingly close relationship between public museums and the super-rich had left less money available for galleries like her own that had nurtured the careers of previously unrecognised artists. She said: “Sponsors would rather have their names on an exhibition by a big name artist in an established museum.”

Anders Petterson, founder and managing director of art market analysts ArtTactic, said the growing dominance of super-rich collectors and mega-galleries was having a detrimental impact on the work being shown in public museums.

He said: “The problem is that diversity is being strangled. The top galleries control the top artists and the top artists are in the top public museums. The model needs to change otherwise we’ll end up in a world where the art we see is controlled by the same people who control everything else.”

Lucy Rose Sollitt, author of a report on the future of the art market, launched at the London Art Fair last week, said the market for risk-taking artists from more diverse backgrounds was shrinking.

Artist Tai Shani, one of the winners of last year’s Turner prize, said the squeeze on public art funding and smaller galleries was contributing to making fine art an unviable career for the less well-off.

“Artists that don’t have commercial practices are not paid [adequately] for their work,” said Shani, a tutor at the Royal College of Art. “A really good fee is considered to be £3,000 for a solo exhibition in a really good institution. That could take you a year to produce. And an artist at the peak of their career might be having two solo shows a year. That’s six grand a year! And that’s really good, often it’s £1,500. Unless you’re able to support yourself with a side job, that’s unsustainable.”