The suspected killer, 41-year-old Andrew Cannon, is expected to be formally charged with the death of Robert Colman, 57, when police complete their investigations following the autopsy report. “The autopsy would reveal the cause of death and also give more clues in helping police determine who the killer was,” one of the sources said.

The murder took place in an elite compound located near the highway to King Khaled International Airport in Riyadh. Cannon fled to Bahrain where he was arrested while attempting to board a flight to London.

Apprehended by Bahrain police, Cannon was handed over to Saudi authorities on March 4. He is currently detained in Riyadh.

Both the victim and the accused were working as teachers for a subsidiary company of UK defense contractor BAE Systems. Both lived in bachelor accommodation in the same building on the private compound.

According to UK newspaper The Daily Mail, Cannon, from Basingstoke, Hampshire, admits there was a fight, but insists he did not cause his friend’s death.

The pair apparently had an argument after getting drunk, with both said to have a tendency to become violent when under the influence of alcohol.

Cannon claims Colman, from Newcastle, struck first, using his fists and an ashtray.

He says he fought back, hitting his friend on the head with a chair. When Cannon was unable to wake Colman the next morning he panicked and fled to Bahrain.

The police are currently conducting investigations to ascertain the circumstances that led to the death and questioning friends of the deceased.