The Celtic star was referenced in a post which contained a monkey gesture slur.
Sinclair hit out at the latest bit of abuse, saying he was “absolutely disgusted” with the act. This follows Saturday’s match at Ibrox where the player was subject to racial abuse from a fan.
Paul Kenny, 28, admitted breaching the Offensive Behaviour at Football Act at Glasgow Sheriff Court on Tuesday.
Police have now confirmed they are investigating this new incident.
A spokeswoman told STV: “A 17-year-old woman is the subject of a report to the procurator fiscal in connection with alleged contravention of section 127 of the Communications Act 2003.”