This story has been corrected. Read below.
Mills took to Twitter late Sunday night to respond to a fan who posted a video clip of the incident, saying that he hoped to "enlighten this confused, hateful fan."
Thanks @thats_Z_Truth. I am a proud Islander. Like my Jamaican Brothers, me & my family in the islands of the Torres Strait have experienced racial slurs for decades. Hope your efforts will enlighten this confused, hateful fan. #BlackHistoryMonth https://t.co/yH3nKlGv4A— Patrick Mills (@Patty_Mills) February 26, 2018
"We are looking into it to see if an identification is possible," a Cavaliers spokesman told ESPN on Monday.
Cavaliers security has various resources it will mine, including video monitoring and word-of-mouth interviews with people sitting in the area behind the basket.
Mills was at the free throw line with 2:29 remaining in the contest when the fan could be heard yelling, "Hey Jamaica called, they want their bobsledder back. Hey Mills, Jamaica just called, they want their bobsledder back!"
Mills, a native of Australia who is black, was not asked about the taunts after the game. His father is a Torres Strait Islander, and his mother is an Aboriginal Australian.
ESPN's Dave McMenamin contributed to this report.