American tennis is embroiled in a racism storm following Young’s clash with Harrison on Monday night.
The two American players clashed on court, with the umpire at one stage getting off his chair to keep the duo apart.
Harrison won the match 6-3 7-6(4).
But afterwards Young took to twitter to vent his anger at his opponent.
“I’m shocked and disappointed, Ryan Harrison, to hear you tell me how you really feel about me as a black tennis player in the middle of our NY match,” Young wrote.
“I thought this was supposed to be an inclusive gentleman’s sport.”
Harrison, ranked 44, quickly responded with a vehement denial of Young’s claims.
He wrote on Twitter: “The accusations made by Donald Young tonight following our match are absolutely untrue.
“I’m extremely disappointed that someone would say this in reaction to a lost tennis match.
“Any video/audio will 100% clear me and I encourage anyone with the available resources to find it.”
An ATP statement read: “The ATP takes any allegations of racial prejudice extremely seriously.
“A further review of all video and audio recording from the match will take place as this matter is investigated further.”
Harrison is due to play Ivo Karlovic in the second round of the tournament in Uniondale, New York.
South Africa’s Kevin Anderson is the top seed in the ATP 250 tournament, with Sam Querrey and John Isner also competing.
Harrison and Young could still end up meeting in the doubles.
Harrison is playing alongside Steve Johnson, while Young is partnering South Africa’s Matthew Ebden.