Authorities in the Russia-friendly self-proclaimed Donetsk People’s Republic announced Friday the death in custody of British citizen Paul Urey of natural causes, the first foreigner to die in the custody of pro-Russian separatists since the start of the war in Ukraine.

Urey, identified by Donetsk authorities as a “mercenary,” died on July 10 from “chronic illness and a depressed psychological state,” Donetsk Ombudsman Daria Morozova said on her Telegram channel.

According to the Ombudswoman, Urey was taken prisoner in April while trying to break through a checkpoint controlled by DPR troops. According to Morozova, he was a professional soldier who participated in conflicts in Afghanistan, Iraq, Libya and Ukraine, led military operations and was also involved in recruiting and training mercenaries for Ukrainian armed formations.

In contrast, Dominik Byrne, co-founder and chief operating officer of Presidium Network, assured ‘The Guardian’ that Urey, 45, was working independently in Ukraine as a humanitarian aid volunteer.

Morozova has also confirmed that Urey was being held in a DPR penitentiary institution at the time of his death. On admission he was diagnosed with insulin-dependent diabetes, damage to the respiratory system, kidneys and a number of diseases of the cardiovascular system.

In addition, the Ombudsman stated that Urey had been suffering from depression for some time “due to the indifference of the British authorities” to his fate in captivity.

“The British representatives ignored even the possibility of negotiating his return as part of the prisoner exchange procedure, nor did they provide the necessary medical supplies through the ICRC,” Morozova added.