Ian Squire, founder of Mission for Vision (LinkedIn)

A British optician, kidnapped with a missionary couple and another optician while working in the Niger Delta of Nigeria, has died.

Ian Squire founded a Christian charity, Mission for Vision, in 2003 to “improve the lives of those living in the poorest regions in the developing world”. Once a year he assembled a team combining opticians and volunteers to give free eye care, predominantly in Africa. He was based in Shepperton, Surrey.

The release of the three other Britons, David and Sheila Donovan and Alanna Carson, was negotiated by the British High Commission and Nigerian government, the BBC reported today. All four had been kidnapped around 2am on 13 October, by suspected militants, while working for a medical charity in the town of Enekorogha.

Dr and Mrs Donovan are reported to have lived in Nigeria for the past 14 years, running a charity called New Foundations, which gives aid to remote villages in the Niger Delta.

Ms Carson, an optometrist, is back with her family in Northern Ireland, according to her employer.

The Foreign Office currently advises against all but essential travel to much of Delta state, saying there is a “high threat of criminal kidnap”.