Manchester United defender Rio Ferdinand believes that football has been put "under the microscope" following a host of incidents regarding racial abuse within the game.
Premier League referee Mark Clattenburg is being investigated by police after he was alleged to have racially abused Chelsea midfielder John Obi Mikel during the Blues' 3-2 defeat to Manchester United on Sunday.
The 37-year-old is also at the centre of a probe by the Football Association after Chelsea lodged a complaint to the Premier League stating that Clattenburg had used "inappropriate language" towards Mikel and Juan Mata.
Ferdinand tweeted: "Will be interesting to see how this alleged 'race' or 'insulting' language episode pans out,our game is under the microscope like never before."
This latest incident comes after Ferdinand's brother Anton was the subject of racial abuse from Chelsea captain John Terry, who is currently serving a four-match ban.