A painting by Mexican artist Frida Kahlo, which recently resurfaced after being hidden from the public eye for 60 years, is set to sell this week for up to $US2 million ($2.7 million).

The unfinished painting, Niña Con Collar (Girl with Necklace), was painted in 1929 when the artist was just 22.

The only evidence of its existence was a black-and-white photograph.

But earlier this month it emerged that the painting had been kept hidden away, "beautifully preserved", in the bedroom of a California house since the 1950s.

The owner — a former personal assistant of Kahlo — was gifted the painting in 1955, the year after Kahlo's death, by her widow Diego Rivera.

Now in her 90s, the owner approached Sotheby's, and the painting will now form part of the auction house's Latin America: Modern Art sale on Tuesday.

It is expected to sell for $US1.5 million to $US2 million.

Head of Latin American Art at Sotheby's, Axel Stein, said in a statement: "I have known Niña Con Collar since 1988 when I saw the black and white photograph."

"I never imagined it would surface and turn out to be such a beautiful and warm painting," he said.

The subject of the painting is an unknown girl of about 13 or 14 years of age.

Sotheby's said the work, "with the subject's direct stare from under her spreading monobrow and the rigid symmetry of a frontal pose", was reminiscent of Kahlo's later, celebrated, self-portraits.

"Indeed, with those elements as well as her dress and jewellery, Niña Con Collar is nothing less than the seed of many self-portraits that Kahlo will produce thereafter in her signature style," Sotheby's said.

Earlier this year, Kahlo's 1939 painting Dos Desnudos en el Bosque (La Tierra Misma) sold at a Christie's auction for $US8 million ($10.9 million).