Police were then called about 6.40pm when she turned up on Tomahawk Rd. After police arrived at the scene they saw her swimming away, Acting Senior Sergeant Paul McLaughlan said.
Mr Fyfe said her actions showed the strength of a sea lion's maternal feelings. She could continue the search for a week or more, he believed.
The pup was born at Tomahawk and DoC had tried to protect it, Gem and its father with a fence and by moving the sea lion family down the beach further away from the public.
An autopsy on the pup at Massey University confirmed it died of disease but tests have yet to determine what it was.
Few pups have been born along Otago's coast this summer.