Francis Bacon portraits held privately sold for £30m

Self-Portrait 1975 was painted at the height of Bacon's career

Two self-portraits by Francis Bacon kept hidden in a private collection for many years sold for a combined £30m at a sale at Sotheby's in London.

Self-Portrait (1975) and Three Studies for Self-Portrait (1980) were known to exist but it was not known who owned them.

The descendents of the collector decided to put them up for auction earlier this year.

The sale also saw Andy Warhol's One Dollar Bill fetch £20.9m.

Bacon's Self-Portrait 1975 sold for £15.3m, while the triptych Three Studies for Self-Portrait reached £14.7m.

But the artist's Study for a Pope I failed to attract high enough bids to meet the reserve, having had an estimate of £25-35m.

It was one of six pope paintings he created for an exhibition at the Tate in 1961.

Andy Warhol's One Dollar Bill (Silver Certificate) was the most lucrative lot of the night

"It wasn't the night for that one picture," said Oliver Barker, Sotheby's senior international specialist in contemporary art.

The contemporary art sale reached total sales of £130.4m on the night.

Mr Barker had previously described Bacon's self-portraits coming in to public view as "a pretty extraordinary collecting moment".

"We knew of the existence of the paintings but simply had no idea where they could be. The first time I saw these paintings it was such a wonderful awakening. They're both so luminous."

Chicken and egg

Self-Portrait (1975) was painted at the height of Bacon's career, in the period which followed the suicide of his former lover George Dyer in 1971. Although Bacon was in his 60s, he looked much younger in the work, having dyed his hair and worn make-up as he grew older.

Four Eggs on a Plate was painted for the late Dowager Duchess of Devonshire

Three Studies for Self-Portrait (1980) shows him with downcast eyes, increasingly haunted by the inevitability of death.

Lucian Freud's Four Eggs on a Plate, which he painted for his friend the late Dowager Duchess of Devonshire, as a nod to her love of chickens, was also part of the sale.

She kept chickens on her Chatsworth House estate and would take Freud eggs whenever she visited London, leaving them on his doorstep if he was not in.

A Bacon painting featuring his friend and fellow artist Lucian Freud, became the most expensive artwork ever sold at auction when it fetched $142m (£89m) in New York in 2013.