The Oxford Murders (2008) on Netflix

Martin, a PhD student in mathematics, enrolls at Oxford in the hope of meeting his mentor, Professor Seldom. The young man manages to find lodging at Mrs. Eagleton's but in this house a stifling atmosphere prevails due to the landlady's attitude. Indeed Mrs. Eagleton, who happens to be a friend of Seldom's, is a haughty and unsympathetic woman who also stifles her daughter Beth. At the university, things do not fare much better as Martin is put in his place by his idol during one of Seldom's lectures. But his private life changes for the best as he starts an affair with Lorna, a beautiful girl he met during a game of squash. One night Seldom and Martin who find themselves at Mrs. Eagletons's discover her dead body. They are interrogated by the police. Soon afterwards they decide to lead their own private investigation...