Poems and letters written by former Poet Laureate Ted Hughes which have never been seen in public before have been bought by the British Library.

The material is contained in an archive, purchased for just under £30,000, which belonged to the late poet’s sister Olwyn Hughes.

Literary gems include 35 draft poems – three of which have not been published before – and 41 letters from Hughes to his sister.

The three unpublished poems are thought to date from the late 1950s and early 1960s and are called Lines In Mid-Air, Snatchcraftington Addresses and Eden.

The letters date from 1954 to 1964 and shed light on Hughes’s feelings about living in the US, life with Sylvia Plath and his opinion on other poets and writers.

In one letter, written in 1957 after leaving post-war Britain for Massachusetts, he complained how “luxury is stuffed down your throat – a mass-produced luxury – till you feel you’d rather be rolling in the mud and eating that”.

The archive also contains four draft poems, all of which have since been published, by Mr Hughes’s wife Plath, who killed herself in 1963.

Hughes’s unpublished material includes a partial hand-written draft of an untitled play. Helen Broderick, curator of modern literary manuscripts at the British Library, said: “This exciting new acquisition provides a real insight into the early careers of both Ted Hughes and Sylvia Plath as they sought publication and recognition for their work.

“Hughes’s insights into life in America are particularly fascinating and the archive complements the British Library’s existing Hughes collections by covering this key period of change and development in his life.”

The archive, purchased for £29,500, will be catalogued and made available to researchers at the British Library by next year.