Singh, a 33-year-old Sikh who comes from Singapore and has Indian heritage, took charge of Chelsea's International Champions Cup loss to Inter Milan at the weekend.
The referee enjoyed a controversial game, awarding Inter a first half penalty and then incorrectly ruling Michy's Batshauyi's late goal out for offside.
During the game, a number of people took to various social media plaforms, including Twitter to launch foul, racist abuse at the official.
It is understood that members of the public have since contacted Kick It Out who have now launched an investigation.