Colourful affair: unseen $20m painting of Picasso's lover auctions in June

A 1935 Picasso work donated to an Australian university is coming to auction this summer.

Jeune fille endormie will head to Christie's in London on June 21 with a top end estimate of $20m.

It had been anonymously donated to the University of Sydney by a US philanthropist, on the proviso that its sale would fund scientific study.

The university has announced that the money will be put towards research into diabetes, heart disease and obesity.

Picasso's muse and lover, Marie-Thérèse Walter, is the subject of the work, which has not been seen in public for more than 70 years.

"This is an absolute jewel of a painting by one of the great artistic geniuses of Western art," said Christie's Giovanna Bertazzoni.

Picasso met the 17-year-old Marie-Thérèse Walter outside a Paris Metro station

Picasso was prolific, offering entry level investors the opportunity to pick up works on the private market for relatively modest sums.

Although the great artist has spanned both ends of the market. Picasso's Nude Green Leaves, and Bust sold for a world art auction record of $106.5m, last year.

It too featured Marie-Thérèse Walter as its subject, with whom Picasso had an affair during the 20s and 30s.

Femmes lisant (deux personages), another Picasso work of Walter, is coming to Sotheby's on May 3 in New York with a top end estimate of $35m.