A refugee detained in Papua New Guinea says guards transferred to Manus Island from Australia's other detention centre on Nauru incited this week's riot.
About 60 asylum seekers and guards came to blows after an argument over food quality.
It was the second time a fight had broken out over food in the centre in as many months.
The refugee from Iran, Amir Taghinia, said the new guards had little sympathy for the asylum seekers who were facing repatriation after four years in detention.
"There has been stimulation from the guards, quite bad treatment. Recently they have brought some Wilson officers, the Australian ones, that used to work in Nauru. They are not familiar with the situation, they don't know how to handle the situation on Manus Island," Amir Taghinia said.
Mr Taghinia also said repatriations and forced deportations of asylum seekers denied refugee status had created tension in the detention centre.