'Elton and George are the new Medicis: they have money, influence and no taste'

Between them they own art worth approximately £1bn. If an Emin or Hirst is not on public display, the chances are it's on the wall of the warehouse of one of the new British collectors whose fabulous wealth is funding a contemporary art boom in much the same way as the Medicis dominated 15th-century Florence or the Guggenheims 20th-century New York.

Now, like their predecessors, today's collectors are turning to philanthropy and opening free art galleries or loaning out work so their collections can be aired in public.

The singer George Michael and his partner Kenny Goss have just launched the Goss-Michael Foundation in Dallas, Texas, with a tribute to Tracey Emin, displaying the 25 Emin works that form part of their $200m (£98m) collection. In November the space will showcase the pair's Damien Hirst pieces.

Elsewhere, Anita Zabludowicz and her property-magnate husband, Poju, who are worth $2bn, are putting the finishing touches to their gallery in Chalk Farm, north London.

Elton John and his partner David Furnish own the greatest private collection of 20th- and 21st-century photography. A private gallery is being built to house it in Windsor, but friends say they are looking to give the public a chance to see the work, beginning with an exhibition at the Baltic Centre for Contemporary Art in Gateshead in September featuring the 100-photograph Thanksgiving installation by Nan Goldin. "Elton purchased Thanksgiving in 1999," Jane Jackson, curator of the collection, said. "It's very biographical, speaking about her life and addictions and her relationship with it. When [Elton] saw it he said, 'I have to have this. I've been there.' This is a chance for people to see this kind of work firsthand. And Elton's name brings in people who don't normally go to a gallery."

Frank Cohen, the self-made millionaire dubbed "the Saatchi of the North", opened his gallery in Wolverhampton in January. Its third exhibition, also in September, will display the work of, among others, Jake and Dinos Chapman. Cohen has been collecting British art for 35 years. "Damien Hirst was seven when I started," he said. "I had all this art and I thought: 'What's the point if I can't show it?' Either I've got a good eye or get them early doors. I think I've got a good eye."

Not everyone is appreciative of the new Medicis, however. Mutterings in the art world accuse them of driving up prices by competing against each other – pricing out public galleries, which now face historical gaps in collections. Others say they are skewing the art market, making it top-heavy with Hirsts and Emins and leaving no room for younger, unknown artists.

The art critic Brian Sewell said: "I think it's sheer vanity. Most of them know fuck all about art. What happens with these museums and galleries is that they all have the same stuff. Saatchi used to buy the whole work of an up-and-coming artist. The artist [then] just disappeared from the scene. Now it's the reverse. Saatchi or Cohen buy something and everybody else rushes to buy it."

The collectors deny that theirs is a malign influence. Filippo Tattoni-Marcozzi, curator of the Goss-Michael collection, points out that the Dallas gallery is free. Cohen's gallery is also free, and the Zabludowicz gallery will charge £5 for a yearly membership but will be free to local residents. "There are people who tend to speculate in the art world," he said. "But I don't think the real collectors who are doing something philanthropic are part of that game." And Elizabeth Neilson, curator of the Zabludowicz collection, added: "We're concentrating on the emerging end of the market. We offer a platform for those artists."

Interesting? Click here to explore further