Four West Papuan community leaders were arrested on Wednesday after they sent a letter to the Biak police station, informing them of a procession planned to welcome the sacred water and ashes delivered by the Freedom Flotilla and to commemorate the 15th anniversary of the Biak Massacre.

In a press release issued Thursday, the Freedom Flotilla to West Papua organisers revealed the names of the four arrested community leaders. Their names were given as Piet Hein Manggaprouw, 56; Klemens Rumsarwir, 68; Yoris Berotabui, 36; and Yan Piet Mandibodibo, 30.

Reports say that the four men are being held in separate cells and questioned by Indonesian authorities. Police said they will be charged with treason, and if found guilty they could end up serving maximum sentence of life imprisonment.

Their arrest relates to the cultural exchange that was reported last week when sacred gifts carried by the Freedom Flotilla to West Papua was handled over to West Papuan community leaders in a clandestine ceremony held, dodging the Indonesian navy.

The release said Federated Republic of West Papua (FRWP) Deputy Prime Minister Frans Kapisa and Minister of Defence Elieser Awom attended the cultural exchange with the Freedom Flotilla in which they received the sacred water and ashes as part of a ceremony of symbolic re-unification of the cultures and struggles of Indigenous Australians and West Papuan peoples.

Messrs Kapisa and Awom had intended to travel to Biak carrying the "sacred offerings." The four men arrested were planning a welcome ceremony on their arrival, the release added.

Meanwhile, in Manokwari, hundreds of people celebrated the arrival of the cultural gifts. The release said, the celebrations were "peaceful and jubilant celebration of Papuan culture."

However, unlike the Manokwari celebration, the Biak event was planned to have a more sombre tone as it also planned to commemorated the 15th anniversary of the Biak Massacre, an incident in which hundreds of West Papuans were allegedly killed and their bodies dumped at sea by the Indonesian military.

The release quotes sources saying that the Indonesian police had planned to capture Kapisa and Awom on their arrival in Biak airport for the event. However, the two senior Papuan leaders cancelled their travel plan to evade arrest.

"This action in Biak was to celebrate our Papuan identity and commemorate our history. On paper Indonesia claims to be a democracy and allow for Papuan identity to be expressed, but in practice, they arrest us and kill us even though we are a peaceful movement," said Amos Wainggai, a West Papuan refugee who had travelled with the Freedom Flotilla and participated in the ceremonial handover.