A British aid worker who was detained by Russian separatists in Ukraine has died, a family member has told Sky News.

Paul Urey is believed to have died five days ago “due to sickness”, according to information his family has received from the Foreign Office.

He was charged with committing “mercenary activities” after being captured in the self-proclaimed Donetsk People’s Republic (DPR) in eastern Ukraine.

Mr Urey, 45, was seized at a checkpoint outside the southeastern city of Zaporizhzhia on 25 April alongside Dylan Healy, 22, a fellow British volunteer.

The Foreign Office condemned the exploitation of prisoners of war after Mr Healy and fellow Briton Andrew Hill were held by Kremlin forces in eastern Ukraine charged with “mercenary activities”.

Linda Urey, Mr Urey’s mother said in a post online that she is “absolutely devastated”.

Daria Morozova, who has the title of human rights ombudsman in the DPR, said on social media that Mr Urey had been suffering from diabetes and respiratory, kidney and cardiovascular issues.

She said: “On our part, despite the severity of the alleged crime, Paul Urey was provided with appropriate medical assistance. However, given the diagnoses and stress, he passed away on July 10.”

Mr Urey’s daughters had told Sky News they were preparing for the worst after they learned he had been held by Kremlin forces in April.

They said they did not know he was in Ukraine until they learnt of his capture by the Kremlin.

Two other Britons and a Moroccan man who were captured while fighting for Ukraine have been sentenced to death in the DPR for mercenary activities.

The DPR is a breakaway entity which is recognised only by Russia, Syria and North Korea.