The PSNI have forwarded a report to the Public Prosecution Service in relation to the behaviour and symbols displayed by one band taking part in the Relief of Derry parade in the city on Saturday.
Police have confirmed that an investigation has been launched following the Apprentice Boys event in the city on Saturday, but have not confirmed the name of the band.
The PSNI meanwhile said they will also be reporting a number of individuals in relation to an unnotified protest in the city.
During the overall policing operation on Saturday, five people were arrested of suspicion of public order offences. They were taken into custody and are said to be assisting police with their enquiries.
A PSNI spokesperson said on Saturday night: “Police will be working with the event organisers and the community in the coming days to examine the issues emerging from today’s parade.”
Meanwhile Sinn Féin Councillor Christopher Jackson has called on parade organisers and the PSNI to explain why they failed to remove a band wearing what he described as “provocative symbols” from the parade.
Colr. Christopher Jackson said: “The PSNI and the organisers must explain why, after giving an assurance that no provocative symbols would not be tolerated, this band were allowed to march on the parade,” he said.
“Sinn Féin will be raising this incident with the Parades Commission and the police to ensure it does not happen again.”
Around 8,000 people took part in the Relief of Derry commemoration with thousands more spectators.
There was a heavy police presence on the ground in the city centre. The day passed off in relative peace but there were disturbances on Saturday night when petrol bombs were thrown.