A large humpback whale which was tangled in rope off the Far North coast has been freed this afternoon.

Department of Conservation staff were able to cut free the debris on the tail of the 12-metre long, 30 tonne whale at 3.30pm, spokeswoman Carolyn Smith said.

The whale was first spotted entangled in rope and debris in Doubtless Bay on Monday.

Staff began a rescue attempt yesterday, and again this morning at 8.30am, managing to secure a hook on the rope.

Rescuers followed the whale until it tired itself out before they approached to cut it free.

Immediately after its release, the whale headed "steadily out to sea," Ms Smith said.