Solomon Islands police says they confiscated a West Papuan flag at the Melanesian Arts Festival to stop any provocation aimed at the Indonesian delegation.
Ben Didiomea had his flag taken by police over the weekend after he held it up in front of Indonesia's festival stall to protest its inclusion at the event.
A video on Facebook shows Mr Didiomea - who was part of a group of demonstrators - holding up West Papua's Morning Star flag as Indonesian officials tried to move him away from the stall.
He was then approached by Solomon Islands Police who confiscated the flag.
Mr Didiomea said he had been standing in solidarity with fellow Melanesian people of Indonesia's Papua region, where the Morning Star is banned.
He said the Melanesian Arts Festival, which Honiara hosted over the last ten days, was not intended as an Asian festival.
Police issued a statement saying the flag was removed to prevent provocation of the Indonesians, reminding the demonstrators that it was not a political event.