A young orca which became separated from its pod in Tauranga Harbour has died.

The calf named Bob died in the early hours of this morning confirmed Conservation Minister Maggie Barry.

The young orca after it was rescued and put into a pool.

'Sadly the calf lost its battle overnight despite the best efforts of a team of rescuers,” Maggie says.

'I send my sympathies and commiserations to the many people who have worked exhaustively over the last week to try to save the young whale. It was an effort made in the best spirit of cooperation and conservation of the natural world.”

The calf, estimated to be between six months and a year old, had been seen in the Tauranga area since July 14.

A tactical response group including staff from the Department of Conservation, the Orca Research Trust, local iwi and community had worked together to attempt a rescue.

With its health deteriorating due to dehydration and malnutrition, it was moved to a land-based pool two days ago.

The orca was initially fed electrolytes and water through a tube and later was given a fish slurry. It appeared to make good progress with rehydration but sadly was unable to return to full health.

'Rescue and release of an orca this young would have been a world first,” Maggie says.

'The chances of success were always slim, but those who gave their time and effort to the calf should be proud of their efforts.

'I understand the tactical response group will make arrangements for an appropriate farewell and will not be making any further statements until these are confirmed.”