Tauranga has received a surprise visitor - a rare and highly venomous sea krait.

The creature was discovered at the Tauranga Bridge Marina on Sunday, and has been identified as a banded sea krait.

"We had an unusual visitor the other day," the marina says on Facebook.

"Sea snakes and kraits are occasional visitors to New Zealand's waters, arriving here naturally from time to time on ocean currents.

"Please be aware sea snakes and kraits are highly venomous but, as they are docile creatures, there is no record of anyone in New Zealand being bitten."