A collection of 20th century British art patiently assembled over a lifetime by an Oxfordshire woman is expected to fetch about £330,000 at auction.

The collection of 47 works of art, which will be auctioned at Christie’s South Kensington in London, has been put up for sale following the death last year in her 90s of artist and former actress Olga Davenport.

Mrs Davenport and her late husband, journalist and economist Nicholas Davenport, lived in a Tudor house, Hinton Manor, at Hinton Waldrist, near Kingston Bagpuize.

During a successful post-war film career, she appeared in films including 1946’s Caesar and Cleopatra, with Vivien Leigh and Claude Rains, and 1951’s A Christmas Carol, with Alastair Sim.

The most valuable work in the Davenport collection up for sale is a double-sided oil painting by Royal Academician Sir Terry Frost. The pictures are called Blue and Red Quay and Movement, Yellow and Green. Alone, this is expected to fetch up to £80,000.

A gouache by Royal Academician William Scott called Study For Berlin Blues I is valued at between £10,000 and £15,000.

In March 2005, the Daily Telegraph described Scott — who died from Alzheimer's Disease in 1989 — as “....one of the hottest artists in the flourishing market for 20th century British art.

Average prices for his paintings have quadrupled in the past four years.”

The Davenports befriended Scott and he was so fond of Mrs Davenport that he designed and made for her a 22 carat gold bracelet and matching ear-rings. These are expected to fetch up to £1,500.

But the pre-sale estimate could turn out to be cautious – a painting by Scott, Bowl, Eggs and Lemons, sold for more than £1m last year.

Another painting by Patrick Heron, Violet Brown Ochre Lemon & Black, is expected to sell for up to £60,000.

It was a gift from Mr Heron to Mrs Davenport.

A Christie’s spokesman said: “Of the pictures assembled by Mrs Davenport and offered in this sale, each entered her life through her own sensibility, taste and sometimes sheer fortuitousness “Her collection helps us to define an era, yet her choices were not completely representative. She was not a democratic collector, selecting a signature piece by each of the leading artists.

“As an artist, she entered into exclusive dialogues and relationships with some of the greatest British modernist artists of the epoch and in turn acquired a unique selection of works that she bought or was gifted directly.”

Mr Davenport wrote the City column for The Spectator magazine. In the 1930s, he helped finance a number of films, including Pygmalion, starring Leslie Howard and Wendy Hiller.