An Oxford University don will not be prosecuted in connection with the death of a professor, the Crown Prosecution Service (CPS) has said.
Devinderjit Sivia, 49, was arrested at his home in Southmoor, Oxfordshire, on suspicion of murder in January after police discovered the body of Professor Steven Rawlings, 50, there.
The two academics had been friends for 30 years and had published a book together. Dr Sivia had been due to answer bail on Wednesday following a police investigation into the death.
Baljit Ubhey, Chief Crown Prosecutor for Thames and Chiltern CPS, said: "Following inquiries by Thames Valley Police, I have concluded, in accordance with the Code for Crown Prosecutors, that there is insufficient evidence to put before a court.
"Professor Steven Rawlings died at the Oxfordshire home of a friend on Wednesday January 11 2012. A post-mortem examination was conducted, but was inconclusive and further tests were required.
"I extend my sincere sympathies to Mrs Rawlings for the death of her husband. An inquest will take place in due course."
Prof Rawlings was said to be a well-respected and liked academic. Dr Sivia and Prof Rawlings had published the book Foundations Of Science Mathematics together in 1999.
Tributes were paid to the St Peter's College academic in the wake of his death, with Vice Chancellor of Oxford University Professor Andrew Hamilton saying the entire university community had been "profoundly saddened and shocked" by his "tragic and untimely death".
Former BBC Radio 4 controller Mark Damazer, now Master at St Peter's College, said Prof Rawlings was a "much-liked and admired tutor".
Prof Rawlings' widow, Linda Rawlings, rallied to support Dr Sivia following his arrest. In a statement issued through Thames Valley Police, Mrs Rawlings said: "I do not believe that Steve's death is murder and I do not believe Devinder should be tarnished in this way."