Auckland Harbourmaster inspecting Manukau Harbour for oil spill after massive fire

The Auckland Harbourmaster has been deployed to inspect the Manukau Harbour to determine whether any oil spilled as a result of yesterday's huge substation fire in Penrose.

Plumes of thick black smoke billowed above the Southern Motorway from the blaze at the Vector substation, which also damaged the neighbouring DHL building.

Three people were injured and taken to hospital as a result of the fire, one in a serious condition the other two in a moderate condition.

The fire is now out but Auckland Council said it had sent pollution response officers to the site on Friday morning to check on contamination and ensure the clean-up is being done to a satisfactory standard.

It's also deployed the Harbourmaster from Māngere Bridge to inspect potential discharge points into the harbour and assess and contain any potential oil that may have entered the water.

There was a strong smell of burned material at the site this morning.

A burned-out van was visible between the substation and the DHL building, which also had clearly visible damage to one of its exterior walls.

DHL workers could be seen taking large fans into their McNab Street warehouse to disperse the smell.

Fire and Emergency is yet to confirm the cause of the fire but yesterday, FENZ assistant district commander Barry Thomas told TVNZ that three Vector workers were carrying out maintenance at the substation "when there was an incident".