Liverpool are investigating claims that fans were mistreated by Spanish police with some allegedly assaulted and denied entry to the stadium before the 3-3 Champions League draw in Seville.
The match kicked off with almost half the away section still empty with reports of delays getting in and supporters being turned away or let in and being told to sit in any seat rather than the one they had been allocated.
There were also claims on social media, which have not been verified, of fans being assaulted by police.
"Following detailed and troubling accounts given by Liverpool supporters attending the match against Sevilla last night, the club is seeking to establish the facts regarding their treatment at the hands of the host stewards and local police force," said a Liverpool spokesman.
"The safety and security of our supporters is our paramount concern and we intend to gather all the relevant information before responding further."