OXFORD, England (AP) -- It seemed like a shocking crime: An Oxford University academic was found dying in the home of one of his closest friends, who was promptly arrested by police on suspicion of murder.

But on Friday the direction of the attention-grabbing investigation into the death of Steve Rawlings seemed to turn, with his friend and fellow academic Devinder Sivia released on bail and a police announcement that the autopsy had proved inconclusive.

The cause of death was not clear _ leaving all possibilities open.

Then came the dramatic statement from Rawling's widow, Linda, who said in a statement delivered by police late Friday that she believed the incident was the result of a horrific accident, not foul play.

``I do not believe Steve's death is murder. I do not believe Devinder should be tarnished in this way,'' the widow's statement said.

Police have yet to rule out a murder case, telling journalists that all possibilities are still being investigated.

``This is a tragic incident and our investigations are ongoing to establish the cause of death,'' said Detective Superintendent Rob Mason, urging patience while inquiries continue.

The case baffled family and friends. Rawlings, 50, and Sivia, 49, have known each other since they were teenagers in college, according to police, and have been friends for decades.

In 1999 the pair co-wrote an introductory-level math book, ``Foundations of Science Mathematics,'' which was published by the Oxford University Press.

What exactly happened between the pair late Wednesday night, when police and paramedics were called to Sivia's home, remains a mystery.

A local paper, the Oxford Mail, said that Rawlings was already dying by the time officers arrived to the house in the village of Southmoor, just outside Oxford.

Even though some signs now point to an accident, the possibility that an Oxford academic had been murdered at the home of one of his colleagues made front page news in the British press.

The venerable university is the English-speaking world's oldest and has schooled generations of thinkers, leaders, scientists and artists. Its gothic spires are familiar parts of popular culture, as are its system of colleges, first established in the 13th century.

St. Peter's College, where Rawlings taught calculus to first-year undergraduates, released a statement saying it was ``deeply shocked and saddened'' by the news and that ``our thoughts go out to his wife Linda, his family, friends, colleagues and students.''

Life outside St. Peter's _ whose alumni include filmmaker Ken Loach and former U.S. Speaker of the House Carl Albert _ continued as usual Friday, although few students spoke to journalists waiting outside the school's wrought-iron gate.

When asked whether the professor's death was on students' radar, one young woman replied: ``Not massively.''

Those outside the university community professed only vague awareness of developments.

``If you don't belong to the college, you wouldn't know him,'' said 75-year-old Pat Sawyer, who used to work as a cleaner at nearby University College.

Rev. Martin Wellings, whose church is next door to St. Peter's, said he was only just finding out the news and wasn't surprised that word was still filtering out.

Wellings said that Oxford was formed of ``a series of interlocking communities'' of which the college was only one.

``We may see more shock as the news percolates out,'' he said.

Back in Southmoor, where police were combing through Sivia's house searching for evidence, onlookers expressed disbelief.

``I've known Devinder for a number of years,'' neighbor Duncan Logan, 52, was quoted as telling the Mail. ``And he's a lovely chap.''