An archive of material relating to the work of writer and painter Christy Brown, best-known as the author of My Left Foot, is to remain in Ireland after being purchased jointly by the National Library of Ireland and the Little Museum of Dublin at auction in London yesterday.

The archive sold for £37,500 (€44,733) at a Bonhams auction in Knightsbridge. It is understood that members of the extended Brown family in Dublin were the vendors.

The archive includes a previously unseen collection of sketches, paintings and unpublished poems by Brown as well as a large cache of correspondence and personal effects including his birth certificate and a passport. The pre-sale estimate was £30,000 to £40,000.

Commenting on the acquisition, Minister for Arts, Jimmy Deenihan praised the joint purchase as a "wonderful example of our cultural institutions working together" and said they had ensured that "a wonderful piece of our cultural and literary heritage, will be preserved for, and made accessible to, the people of Ireland".

Christy Brown, who died in 1981, aged 49, was best-known for his autobiography My Left Foot which subsequently inspired the 1989 Oscar-winning film starring Daniel Day-Lewis.

Brown, from Kimmage in Dublin, was diagnosed with severe cerebral palsy following his birth in 1932. He achieved international fame when he overcame his disability to write, draw and paint using his left foot. He wrote poetry and a series of novels including Down All The Day published in 1970.

Bonhams said the core of the archive consisted of some 40 letters from Brown to Katriona Delahunt “the social worker who first met Brown in his adolescence and nurtured his love of writing and painting”.

The archive also includes letters from Brown to members of his family and letters to him from both his American friend and lover, Beth Moore and Dr Robert Collis who first arranged treatment of his cerebral palsy.

In 1972, Brown, by then a chronic alcoholic, married Englishwoman Mary Carr and the couple moved to live in Somerset.

The archive includes a letter he wrote a few days before his death in which he bluntly acknowledged his alcoholism: “The simple truth of the matter is that I just don’t want to quit, I don’t want to be ‘cured’ or rehabilitated, I am in love with the whole process of inebriation and shun all semblance of ‘normal’ life like the plague”.

Brown was aware of the consequences and wrote: “From being merely maudlin once upon a time in my cups I’m becoming increasingly aggressive, destructive and positively violent, making entirely unprovoked assaults on Mary and furniture in my booze-laden rages. It’s a deplorable situation and one that cannot go on indefinitely; I’m sickenly [sic] aware of what the consequences are bound to be, but amazingly I don’t seem to care or at any rate will let myself care.”

He choked to death at dinner 11 days later on September 7th,1981.