Oil slicks from the Mikhail Lermontov have been spotted on the sea surface 26 years after the Russian cruise ship sank in the Marlborough Sounds.
Marlborough District Council says the slicks were first seen a couple of months ago.
Harbour master Alex van Wijngaarden said there were three distinct areas, but the slicks were dispersed well before they got near land.
The Mikhail Lermontov grounded on rocks and sank in 1986 at Port Gore.
The marine engineer in charge of pumping the oil from the wreck says 2000 tonnes were removed and anything left would be minimal.