A 1920s hitman tried to assassinate a senior policeman by sending him poisoned chocolates, records released by the National Archives have shown.
Sir William (left) tracked down the chocolate poisoner Tatam (right)
Walter Tatam laced walnut whip chocolates with weedkiller in a plot to kill Metropolitan Police commissioner Brigadier-General Sir William Horwood.
Sir William thought the chocolates were a gift from his daughter Beryl and ate them - but survived the poisoning.
He launched an investigation which eventually lead to Tatam's conviction.
Sir William had eaten the sweets - which arrived in a package at his office in November 1922 - after a hearty lunch of pork and apple sauce, bread and butter pudding and Guinness, the records showed.
Within minutes of eating them, he was in agony, and called for a glass of brandy to help control the pain.
His assistant Edith Drysdale insisted his condition had been caused by a musty walnut, but the police chief suspected foul play.
He inspected the package the poisoned chocolates had come in with his magnifying glass.
When he realised he may have been deliberately poisoned he said: "My God. Perhaps I have been doped!"
Sir William's investigation eventually found Tatam responsible for the attempted assassination.
He found Tatam had also targeted other leading police officers with chocolate eclairs laced with the poison.
The hitman's motive was never discovered, but he was charged with intent to commit murder.
In court he said he heard voices coming from hedges, and was found to be insane.
The records were made public through the Archive Awareness Campaign, which aims to promote information held in the UK's 2000 archives.