Chelsea defender Ashley Cole

AP

Derbyshire Police have opened an investigation into alleged racist comments against Chelsea defender Ashley Cole on Twitter, four days after club teammate John Terry was cleared of racial abuse.

Cole, who defended Terry in court from charges made by Queens Park Rangers defender Anton Ferdinand, was reportedly referred to as a ''Choc Ice'' by a Twitter user.

The term is believed to mean black on the outside, white on the inside, reports The Associated Press.

Ferdinand's older brother, Rio, who plays for Manchester United, responded to the tweet on Saturday with: ''I hear you fella! Choc ice is classic hahahahahaha!!''

The following day, Ferdinand tweeted: ''What I said yesterday is not a racist term. It's a type of slang/term used by many for someone who is being fake. So there.''