More than 25 cattle found wandering loose on the North Shore have been returned to their owner.

The cows were found on council land on the corner of East Coast Bays Rd and Glenvar Rd at 4am after a concerned passer-by alerted authorities.

Lee Exler, council animal control coordinator, says the herd broke out of a Long Bay farm about 2.5km away before making its way up Glenvar Rd.

"We've never had anything like it happen before," Mr Exler said.

Some of the cows then escaped from the area, prompting alerts from the public.

"Where it's located is two major thoroughfares, so there were a lot of calls at 4am."

"If it was any later in the day, we could have had a major accident."

Council staff spent the morning trying to locate the owner of the animals, after moving them to a nearby farmer's paddock.

Communications adviser Kelly Gunn said the cattle were found in an unfenced area.

"We are lucky that we didn't have cows running all over Torbay," she said.