Hailed as a scientific genius, the electronic engineer Ralph Benjamin, security adviser to Margaret Thatcher and inventor of the precursor to the computer mouse, has died aged 97. The  son of Karl  Benjamin, a leading German Jewish government figure and war hero , Ralph reached England in 1939 and won a scholarship to Ellesmere College, Shropshire. He worked as an electrician’s mate in air raid shelters, later helping convert a factory to build Blenheim bombers. Supported by a Czech businessman, he gained a war-time technical degree at Imperial College London. He graduated with a First and joined the Royal Naval Scientific Service to work on the secret development of radar. In 1944 Ralph learned both parents had died in Auschwitz, and in 1945 took British nationality.

In the post-war Admiralty Surface Weapons Establishment at Portsmouth Ralph initiated a naval command and control system, one of whose key advances was Tracker Ball, the putative computer mouse, patented in his name in 1947.

In 1960 at the age of 37, Ralph became Deputy Chief Scientist at the ASWE, swiftly gaining a PhD for his original work on radar and sonar. In 1971, with a DSc from London University he moved to the Government Communications Headquarters in Cheltenham as Senior Superintendent Director and Chief Scientist. There he helped promote the mathematic basis of the computer revolution, from internet banking to one-click shopping. He was appointed CB (Companion of the Order of the Bath) in the 1980 New Year’s Honours.

Retiring in 1982, he joined NATO as Chief of Communications Techniques and in 1983 was elected a Fellow of the Royal Academy of Engineering. He published over 80 learned-society papers in diverse subjects. Defence luminaries attribute to him and colleagues some of the fundamental technologies of the second half of the 20th century.

In 1987 Benjamin became a visiting professor at several universities and led and served on many national and international committees, and advisory councils, winning several professional awards. A fluent linguist and active sportsman, he led the first ascent of the North wall of the Cima di Rosso in the Bregaglia Alps in 1960.

In 1951 he married the psychologist Kathleen Ruth Bull. Their elder son John died in a tragic skiing accident in 1987. His autobiography “Five Lives in One” was published in 1996. Kathleen predeceased him in 2017. He is survived by their younger son Michael.