Orokonui Ecosanctuary staff are closely scrutinising the facility's predator-proof fence, after two stoats made their way into the reserve.

The stoat intrusions were discovered three weeks apart.

Staff believe the fence is secure, but they've become more vigilant since the pests were caught.

Dogs have been walked around the sanctuary and rangers have not found any other unwanted animals inside.

None of the rare, native birds or lizards in the reserve appear to have been harmed by the stoats.

Staff aren't sure how they got in, but they're working to eliminate all possibilities to solve the problem.

Orokonui is home to kiwi, kaka and takahe, among other native flora and fauna.