The San Francisco Jewish Museum has cautioned a security guard after he refused to allow two women to hold hands at an exhibition of the work of prominent lesbian artist Gertrude Stein.

The couple was reprimanded by the guard, who told them they could not hold hands.

Jane Levikow, who witnessed the dispute, noted that the exhibition was centred on Ms Stein's "lifestyle, and relationships". She told the San Francisco Chronicle that the guard's ban was ironic.

The Jewish Museum's exhibition is a companion to a show next door at the San Francisco Museum of Modern Art featuring 150 artworks collected by Ms Stein.

A prolific writer and art collector, born to Jewish-German parents in the United States in 1874, her social circle included Pablo Picasso and Ernest Hemingway.

However even in the cosmopolitan Paris circles she moved in, it was her relationship with Alice B Toklas that captured public attention.

Connie Wolf, director of the museum, said they had also apologised to the couple. She said: "Let me be crystal clear that the CJM has a zero tolerance policy concerning any type of prejudiced or racist word or action."