EXCLUSIVE by JAMES LYONS

Deputy Political Editor

POLICE investigating the death of Christopher Shale are set to quiz up to three of Prime Minister David Cameron's senior aides.

The three, who called Mr Shale shortly before he died, may be called as inquest witnesses.

Mr Cameron's press secretary Gabby Bertin left a message, while the PM's election agent Barry Norton and an unnamed aide both spoke to him on the phone. Toxicology tests will be carried out after a postmortem failed to find a cause of death.

Police said yesterday: "It is normal to speak to anybody who had contact with someone in the hours before their death."