Durden, who came close to quitting the house last Thursday, was called to the diary room at around midnight last night by the show's producers.
After being told that his grandmother had passed away, Durden took leave of his fellow housemates and left the BB house in the early hours of this morning.
Viewers of E4's live streaming were not told the reason for his departure, but the news will be confirmed in Channel 4's programme tonight.
David Emin, advertising director at the Mirror Group, had earlier alluded to "an issue outside the house" which could trigger Durden's early departure.
United Kingdom
Family bereavement cuts short Durden's Big Brother experience
LONDON - PHD co-founder Jonathan Durden has left the Big Brother house to spend time with close family following the death of his grandmother.