The man being held in connection with the death of MP Jo Cox has been named as Thomas Mair, who was described as a “loner” with a history of mental health problems who had previously subscribed to a far-right magazine.

Mair, 52, who was arrested by armed officers shortly after the attack, had spoken about receiving “psychotherapy and medication”, and was described by his younger brother as having “a history of mental illness”.

Despite being born in Kilmarnock, Scotland, a decade-old website posting identified Mair as a subscriber to S. A. Patriot, a South African magazine that was published by the pro-apartheid group, the White Rhino Club.