Etor’s first break came whilst doing a kind of national service in Nigeria, when he realised lots of locals were being hospitalised with food poisoning, because they were trying to preserve things by drying them in open fields.

To solve the problem, he designed and built a kind of “solar oven”.

“It worked incredibly well,” he said, which led to an award from the state government and a job.

That subsequently led him to receive a scholarship to study electrical power at Newcastle University and a PhD at Durham University, before he secured his current job in Bristol.

Sir Steve Webb, the former MP and Pensions Minister, who got to know Etor through the church in Bristol, called his achievements “remarkable”.

“David’s message is very much that people shouldn’t be defined by their upbringing or their background,” he said. “They shouldn’t be written off.”

“I was pinching myself on my way here this morning,” Etor added.

“Nothing good was supposed to come out of me.”