An Oxford University employee and a US professor have been charged with murdering a 26-year-old hairstylist found in Chicago with more than 40 stab wounds.

Somerville College’s Andrew Warren, 56, and Professor Wyndham Lathem, 42, are accused of killing Trenton Cornell-Duranleau in Lathem’s Chicago apartment.

Police announced on Saturday that they had both been charged with first-degree murder after they were returned to the city from California, where they handed themselves in following a nationwide manhunt.

Their charges came after a postmortem examination found the victim, who police say was in a personal relationship with Lathem, had methamphetamines in his system.

Warren, who reportedly lives in Swindon, was suspended from his job as senior treasury assistant after the body of the man, originally from Corunna, Michigan, was found mutilated on 27 July.

Lathem, a microbiologist since sacked by Northwestern University, plans to plead not guilty, according to his lawyer, Kenneth Wine.