Cleveland Police have released a description of Graham Barry Gibson, who they want to trace in relation to the death of a woman in Middlesbrough.
He's believed to be white, in his 40s, 6ft 2in tall, with short dark brown hair. He was last seen wearing a chequered shirt, dark jeans and black trainers.
Police have advised the public not to approach him.
More top news
Temperatures will remain close to freezing.
The prime minister's announcement came as international leaders gather in Paris on the second anniversary of the climate change plan.
Prime Minister Theresa May said in October the Government will shift towards an organ donation system in England which presumes consent.