The country’s Foreign Affairs Minister Luis Filipe Tavares said the migrant boat started its great journey in the West African archipelago.

“There were no Cape Verdeans on board but because the ship began its crossing in Cape Verde we are going to investigate so that other cases do not occur,” Tavares said on TV Wednesday night.

On Saturday, local fishermen found the catamaran, flying the Haitian flag, drifting off the Brazilian coastal town of São José de Ribamar, south of the Amazon River, the Brazilian navy said.

There were 25 migrants – all men – on the boat and two Brazilians, reportedly suspected of being people traffickers.

The migrants came from Guinea, Nigeria, and Senegal on the other side of the Atlantic, the human rights department for Brazil’s state of Maranhão said in a statement.

They had reportedly spent 35 days afloat but there was no immediate indication of what route they had taken.

Brazilian police will investigate possible crimes committed against the migrants and evaluate their legal situation.

Cape Verde, a group of nine inhabited volcanic islands, lies some 500 kilometres (300 miles) off the west African countries of Guinea-Bissau and Senegal.

The islands gained independence from Portugal in 1975 after an 11-year liberation war.