Police have revealed a twist in the story of an assumed attack on broadcaster Barry Soper's son, several months after his other son was stabbed on a night out in the CBD.

Hugh Soper, 21, was not the victim of assault, but actually fell down a steep bank while walking on a track near Zealandia in Wellington, police said.

Barry Soper said he had spoken to police over the weekend, and they told him his son falling down a bank was a possibility, but they were keeping their minds open.

"If that did happen, of course we're all very thankful," he said.

"The problem is that he can't remember anything, he remembers walking home through the bush and next thing he remembered was the police lights, so everyone assumed that he had been attacked."

Hugh, who was "hopefully" being discharged from hospital today with a fractured skull, "genuinely can't remember anything".

"When he was found he was apparently very cold, so he could have been unconscious for several hours."

Hugh was also left with a brain bleed, a broken eye socket, and possibly a broken collar bone and rib.

Soper said his son believed he was assaulted because his cellphone was gone.

"The first thing he can remember is the flashing lights of the police car and an officer shining a torch at him."

A police spokeswoman said Hugh's condition had improved significantly.

"inquiries have established his injuries were sustained as a result of a fall down a steep bank while walking home," she said.

"He was alone at the time of his fall, and was not the victim of an assault."

The incident follows an attack in July when Soper's other son, Henry, was stabbed on a night out in Wellington CBD.

Henry, 23, was leaving a bar in Courtenay Place in the early hours of July 28 when he got into an argument with a man he didn't know, who is alleged to have pulled a knife.

Soper said Henry put his arm up to fend off the blow but the knife went through his forearm, slicing nerves, tendons and damaging an artery.

Bleeding heavily, Henry was taken to hospital.