“Diego y yo” (Diego and I), painted in 1949, “is poised to shatter” Kahlo’s current auction record of US$8 million set in 2016, the auction house said in a statement.

The artwork, which will be the star lot of Sotheby’s big November sale, is also expected to smash the record for a painting by a Latin American artist.

“Los Rivales,” a 1932 work by Rivera, with whom Kahlo had a passionate and tumultuous love affair, is currently the most valuable – Christie’s sold it for US$9.8 million in May 2018.

“Diego y yo” is emblematic of Kahlo’s self-portraits, known for their intense and enigmatic gaze that made the Mexican painter, a feminist icon, famous around the world.

In the painting, Rivera’s face appears on Frida’s forehead, above her distinctive eyebrows and dark eyes from which a few teardrops fall.

The depiction of Rivera, who at the time was close to Mexican actress Maria Felix, as a third eye symbolizes the extent to which he tormented her thoughts, art experts say.

Kahlo and Rivera married each other twice. She died aged just 47 in 1954.

“Diego y yo” last sold at Sotheby’s for US$1.4 million in 1990.