An England fan had his ear bitten off by another after the World Cup game against Uruguay.
The man was left with half his left ear ripped off and bloodied in the incident in Sao Paulo, the Association of Chief Police Officers confirmed. Details of the attack have only just emerged.
Chief Superintendent Rachel Barber said: "We were made aware during the England vs Uruguay match in Sao Paulo that an incident had taken place which resulted in an England fan having a portion of his ear bitten off by another England fan.
He added: "In the immediate aftermath, we managed to make contact with the victim and offered advice and support. The day after the attack, the victim chose to make a formal complaint to the local police and they opened an investigation."
More top news
Cricket stars, celebrities and fans have joined a social media campaign paying tribute to Phil Hughes by leaving their cricket bats out.
Eight out of 10 asthma sufferers are not getting enough clinical care, a leading health charity has found.
Phillip Schofield has revealed that an eccentric fan who wanted to marry him arranged a wedding - leaving him with the bill.