The United States Coastguard in American Samoa says environmental damage from Pago Pago harbour's largest ever diesel spill is minimal.
The New Zealand-flagged Ocean Breeze, which is owned by the Sanford fishing company, leaked close to two-thousand litres of diesel during a ballast removal operation last week.
It's the third incident in three months involving a Sanford vessel in the territory.
The coastguard's Lieutenant Steven Caskey says good weather hastened the clean-up.
"I would speculate that the environmental impact was minimal, again because we were able to contain the spill very quickly and keep the diesel fuel from spreading across the bay. There was a minimal amount of sheen that dissipated from that after the boom was removed. Most of it was very light surface sheen that burned off within a few hours."
Lieutenant Steven Caskey says the Ocean Breeze is still in port undergoing repairs ordered by the coastguard following an inspection.
He says it's possible the coastguard will fine the vessel.