A church warden and a magician were arrested on suspicion of murder in the mysterious deaths of two elderly neighbours 18 months apart in a sleepy Buckinghamshire village.

Peter Farquhar, a 69-year-old retired teacher and university lecturer, was believed to have died of natural causes at his home in Maids Moreton near Milton Keynes in October 2015. The death of 83-year-old Anne Moore-Martin, a retired teacher who lived three doors away, last summer caused police to become suspicious.

After months of investigation, detectives arrested two of Farquhar's former University of Buckingham students. One the men arrested, 27-year-old Ben Field, had been lodging with Farquhar before he died.

Field, a former English literature and journalism student, was arrested on suspicion of murdering the two retired teachers, attempting to defraud them and burglary. The 27-year-old was a deputy church warden at Stowe Parish Church, where Farquhar was a respected and active member who sometimes acted as a lay preacher.

Martyn Smith, a 31-year-old former Buckingham student from Redruth in Cornwall, was also arrested on suspicion of the same offences. Smith, a part-time magician, and Field became close to Farquhar while studying at the independent University of Buckingham.

A few months before Farquhar died, the pair convinced him to publish a handwritten manuscript that he had written 20 years prior. The two men also established a company called Farquhar Studies and named themselves directors.

A third man, 22, was also arrested on suspicion of conspiracy to defraud and false representation.

Neighbours of Farquhar, a Cambridge graduate who taught at Manchester Grammar School for 34 years before moving to Stowe public school and then University of Buckingham, describe him as a fit and active man who took a turn for the worst in the autumn of 2015.

"He was normally very fit and very well - never ill. Suddenly he started to go downhill and was feeling ill," a neighbour who asked not to be named told The Telegraph. "He spiralled downwards and was taken to the Red House Nursing home which is just around the coroner from his home."

He returned home in October 2015 and later died in his sleep. Farquhar's death was not treated as suspicious until May 2017, when his neighbour Moore-Martin became ill and died. Moore-Martin was a former headmistress at a Catholic primary school who had lived in her home for decades.

Neighbours said that days before she died, police conducted door-to-door inquiries asking who she had been associating with. "They wanted to know about her and if she had friends in the area. We asked what was happening and if Ann was alright, and they said 'no, she's not. She's very ill," a neighbour said.

In a statement, a spokesman for Thames Valley Police said: "We have made three arrests in connection with a murder investigation after two elderly residents died in Buckinghamshire. The causes of death are yet to be determined."