Ian Squire, founder of Mission for Vision (LinkedIn)

The Nigerian Army says the leader of a gang responsible for the death of a British aid worker has been killed, the BBC reports.

Peregbakumo Oyawerikumo was arrested by a special military task force. According to the army that task force was then ambushed on its way back to the camp, and Oyawerikumo was killed.

Oyawerikumo was the gang leader who masterminded the kidnap of four British missionaries in Enekorogha, in Nigeria’s restive Delta state, in October.

One of them, Ian Squire, 57, was killed in the early hours of their detention. He died in a hail of bullets after singing the hymn ‘Amazing Grace’ to lift the spirits of his fellow hostages, as World Watch Monitor reported.

The three other hostages, David and Sheila Donovan and Alanna Carson, were released following the payment of a ransom, believed to have come from the Nigerian government.

Squire, a trained optician, 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.