DoC communications advisor Steve Brightwell confirmed it was a seal that was sighted, saying that the fur of the seal and shape of the body are identifiers, alongside a variety of other factors.
"A leopard seal would be considerably larger, does not have external ears like fur seals do and cannot 'walk' as fur seals do because they can't rotate their hind flippers underneath them," he wrote.
Hawley was also concerned by the lack of movement made by the kekeno, as it appeared motionless apart from the occasional bobbing of its head.
Brightwell, however, wrote that seals are prone to relaxing in the water and are robust enough to return to the sea when they are ready.
"When you see them resting in the water with one flipper in the air this is a way they regulate their temperature."
"At this time of year, they are not bound to breeding colonies and can explore widely – including a long way up rivers," he wrote.
Another person that Hawley saw on his walk confirmed that the river is occasionally the resting waters of choice for seals, having seen several there before.
DoC regulates a 'hands-off' kekeno approach to the public, advising people not to intervene with stray seals unless they appear in immediate danger.
This is due to the sometimes aggressive response of seals when they perceive a threat to their environment, and also reflects the Marine Mammals Protection Act.
People are prompted by DoC to keep a distance of at least 20 metres from kekeno, keep dogs on a lead around them and not get between the seal and the water.
