Runaway father Murray Robertson, 57, said he had taken his three children on a six-week nature tour of Tasmania while authorities conducted a nationwide hunt for them.

He said he and the kids stayed with friends and camped around the island state, in what he indicated was his way to reclaim his family.

In an interview with smh.com.au, Mr Robertson painted an ideal picture of the holiday - a scene that contrasted with the worry and fear held by his estranged wife, Philippa Yelland, after the children vanished.

"The children love nature,'' he said of Bokkie, 10, Matilda, 9, and Barney, 7.

"We studied marine life near Hobart. We have been riding bicycles and horses, spending time with chooks and in apple orchards.

"We camped probably nearly a week of the time.''

Asked how the children felt about leaving him today, he said: "It was awful for the children because they are going back to their greatest fear.''

In an interview with Channel Nine before he handed the children over to Australain Federal Police, Mr Robertson showed no sign that he was at fault in the case.

"No one knows the truth of what the children think and feel and dream about," he said.

"I didn't take the children .... the children were desperate to go away with me," he said.

"I could never harm my children. In fact, I could never harm anybody."

Ms Yelland was on her way to Tasmania tonight to be reunited with the three children.

"There's not going to be big hassles about this," she said. "We'll just sort it out and let the children come home safely."

Mr Roberston told smh.com.au that he was pleased with the decision by the Family Court to publish their names several days ago as way of helping to locate them.

He said the court's decision had placed him on guard against being caught by Tasmanian police.

However, he also said: "It set me free to talk to the media.''

The breakthrough in the search came in a phone call from a family friend to the Sydney Channel Nine newsroom yesterday, according to its chief of staff, John Choueifate.

Mr Choueifate said the person called on behalf of Mr Robertson, who wanted to tell his side of the dispute and arrange the hand over of the children to federal police following the Family Court order, which did not empower the AFP to arrest the IT specialist.

Mr Choueifate said Nine acted responsibly, contacted federal police and then worked with Mr Robertson and police to hand over the children in Launceston.