A series of letters of protest by the master of a Fratelli d’Amico Armatori tanker has provided new insight into an oil spill at a refinery in Peru.

The documents emerged nearly two weeks after the spill as the tanker began offloading the rest of its cargo of Brazilian crude in a ship-to-ship transfer.

The 158,000-dwt Mare Doricum (built 2009) has been at anchor off Lima since the 15 January spill, which saw some 6,000 barrels of oil leak from an underwater refinery pipeline after a wave from a massive volcanic eruption in Tonga impacted the unloading procedures.