A stunned father watched on as a massive humpback whale swallowed his son whole before spitting him out unharmed in a hair-raising incident captured on video.

Dell Simancas and his son Adrian were on a trekking and packrafting trip when the extraordinary encounter took place.

The shocking clip shows the father and son paddling in the icy waters of southern Chile.

The whale suddenly breaches the water and appears to swallow Adrian, 24, in one go.

He and his raft disappear from view for several seconds before bobbing back to the surface.

Adrian’s dad calls out to him, repeatedly telling him to “relax” and “hold onto” his raft.

He assures his son: “I’m coming.”

While clutching his overturned raft, Adrian grabs hold of his dad’s canoe and the pair make their way back to shore.

The incredible encounter took place in the Strait of Magellan in southern Chile at abourt 3pm on Saturday.

After their ordeal Dell, 49, said: “I heard a loud sound and when I turned around, my son had already vanished.”

The Venezuelan anaesthesiologist added: “Fortunately, Adrian quickly returned to the surface and although he was in shock, he did not suffer any serious injuries.”

Adrian stated: “I didn’t understand what was happening. I thought it had eaten me.”

The young programmer and musician added: “It’s a tale that seems like fiction. But I lived to tell it.”

He also thanked his father for remaining calm and giving him clear instructions.

The 24-year-old told the BBC: “I was really afraid that something would happen to my dad too, that we wouldn’t have reached the shore in time and that we would get hyperthermia.

“But when I got out, I understood that of course it was probably out of curiosity that the whale approached me, or maybe trying to communicate something.

Despite the magnitude of the incident, both Dell and Adrian, who live in Punta Arenas near where the encounter took place, said they will continue taking part in packrafting expeditions.

But they said they will be more cautious in the future.

Humpback whales range in length from 14 to 17 metres and can weigh 40 tonnes.