In 1972, whilst working at the Sudanese Embassy in London, El-Salahi returned to Khartoum to take a post as Director General for Culture at the Ministry of Information. Although Sudan was under military dictatorship, he felt compelled to accept the position out of duty to his home country.
The following year he became Undersecretary, a tenure that ended abruptly on 8 September 1975when he was accused of anti-government activities and held without trial at the infamous Cooper Prison for six months and eight days. After this experience, El-Salahi left Sudan to live in Doha, Qatar.
El-Salahis imprisonment and self-imposed exile considerably affected the aesthetic orientation of his art. His earlier formal experimentation gave way to a more philosophical practice and his signature earthy colours and expressive forms were replaced by stark, introspective black-and-white images. Prison Notebook 1976 documents his experiences of incarceration. Consisting of pen and ink drawings and poetic prose, this repository of memories served the artist as a therapeutic healing tool.