A South Island council has apologised after two children were left locked in a Central Otago pool for hours during the weekend

Otago Daily Times reports the children aged 10 and 13 were left in the Alexandra Pool's changing room on Saturday night after the facility closed for the evening.

Central Otago District Council community experience group manager David Scoones says staff have a well-established practice of checking the changing rooms - but in this case failed to do a final check.

He says they're taking the matter seriously and will be taking steps to ensure this doesn't happen again.