The US Coast Guard said it is not conducting an investigation into the ammonia leak that caused the evacuation of the main dock and closed the entrance to the Port of Pago Pago two weeks ago.
Port Administration director Taimalelagi Dr Claire Poumele said the source of the leak came from the engine room of the Captain Vincent Gann purse seiner - which was docked at the port.
The vessel was then moved to another location and the port reopened 30 minutes later.
US Coast Guard spokesman Lieutenant Scott Carr said the Coast Guard has talked with the crew of the vessel.
He said there was no subsequent investigation as the amount leaked did not meet the level of a marine casualty.
That threshold is 100 pounds or 45 kilogram whereas the amount leaked from the vessel has been estimated at just 5 pounds.