Rangers defender Borna Barisic was targeted with a bottle as he received treatment during his side's win over Hibs.
The left-back was floored by a wild challenge from Ryan Porteous and TV footage captured a missile being thrown from home end at Easter Road.
Porteous was sent off by referee Nick Walsh as Rangers triumphed 3-0 in a bad-tempered encounter in Leith.
Images show Hibs' Martin Boyle removing the bottle from the pitch and Scott Arfield handing over another, unidentified object to a police officer.
The Leith club had issued a pre-match warning insisting they'd review any CCTV footage if incidents were to occur.
Hibs coach John Potter and Rangers' counterpart Tom Culshaw were also given their marching orders following a touchline stramash in the wake of Porteous' tackle.
The incident follows Rangers captain James Tavernier being attacked by a fan who leapt the barrier during the same fixture last term.
Celtic's Scott Sinclair was also targeted by a Buckfast bottle on the same ground last season.
On this occasion, goals from Ryan Kent, Joe Aribo and Jermain Defoe earned all three points for Steven Gerrard's side as they closed the gap on Premiership leaders Celtic.
Neil Lennon's men had stretched their advantage to five points on Wednesday night with a 2-0 victory at Hearts.
But an impressive display across the city tucks Rangers back in behind their arch rivals, with only two points now separating the teams.
