The 26-year-old Queen’s Park Rangers defender was sent a terrifying letter last week, after it was claimed that Terry called him “a f****** black ****” during a clash two weeks ago.
The England skipper, who earns £170,000 per week could be stripped of his title as captain if the Football Association find him guilty.
The Metropolitan Police has launched an investigation into the letter, which was delivered by hand to the club last Friday.
The content of the letter was so graphic that QPR officials didn’t show it to Ferdinand.
Last night a spokesman for the Met said: “We can confirm we are investigating an allegation of malicious communications.”
Police have told Ferdinand to install a panic button at his home and his close relatives have also been told to take precautionary measures.
Terry has not denied saying the words, but he insists he was asking Ferdinand if he thought he had made a racist remark.