Warnings of toxic shellfish caused by the oil leaking from the container ship Rena have been extended to the Coromandel area.

Waikato District Health Board medical officer of health Anita Bell says people need to be vigilant if they are collecting shellfish off the eastern seaboard of the Coromandel Peninsula.

Anita says people should not collect and consume seafood, including shellfish and fin fish from waters with visible oil contamination and should also avoid any seafood that has off petrol like odours.

Although there is no evidence yet of the oil spill reaching the eastern Coromandel Peninsula coastline, conditions are continually changing.

Maritime New Zealand is collecting and testing shellfish and further advice will be issued in due course.