British police are digging up the grounds of a country property owned by a university professor who was last seen six months ago.

It is believed that Samuel Alexander’s 22-year-old son, Mark Alexander killed his Egyptian born father at their home in Buckinghamshire last August, and then buried the body in the garden of the 2-story red brick home.

During a neighborhood watch meeting in January, residents of Drayton Parslow told a Police Community Support Officer that no one had seen the 70-year-old man in six months.

After searching Alexander’s home last week, police arrested his son in London on Friday on suspicion of murder.

Authorities did not say if the house had been lived in over the last six months or whether Alexander’s body was discovered.

Alexander, who is also known as Sami Yacoub El-Kayoubi, was an English lecturer at the De Montfort University, Bucks, and prior to disappearing he and mark lived in Drayton Parslow.

Mark Alexander is a law student at King’s College University London.