A bizarre video has emerged of an undercover policeman wearing a Celtic top – as he huckles a Liverpool fan during disturbances in Barcelona.
Reds supporters stand accused of pushing locals into a fountain ahead of Wednesday night’s Champions League semi-final.
Liverpool chief executive Peter Moore has called on fans to "act in a manner befitting LFC" after the scenes in the Catalan capital.
Videos have circulated on social media apparently showing individual supporters, in different incidents, pushing locals into a fountain at Placa Reial, just off La Rambla on Tuesday evening.
And one of the clips weirdly appears to shows a police wearing a black Celtic training top arresting a fan.
In it, the punter is being led away by three officers, one of whom is donned in replica kit of the Scottish champions.
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Later in the evening police cordoned off the square and forced all fans back on to the main tourist strip before walking them up the street to Placa de Catalunya, a main transport hub, where they dispersed.
And Moore has pleaded with visitors in Barcelona to represent Liverpool with distinction.
He wrote on Twitter: "We proudly sing that we've conquered all of Europe. But let's treat this beautiful city with the respect that it deserves, and act in a manner that is befitting of LFC.
"By all means have a good time, but we are Liverpool, and as such, let's visit here with grace and humility."
On Tuesday, as thousands of fans began to arrive in the city for the Champions League semi-final first leg, Merseyside Police's dedicated Twitter account for LFC fans tweeted the advice: "Eat, drink and enjoy all areas in the city centre. Respect monuments."
