PRESS ASSOCIATION -- Prince Harry has revealed he did not inform the Queen of his daring trip to the Arctic in which he battled sub-zero temperatures in a punishing charity trek.
The 26-year-old has told of his father's nerves about the trip and suggested many of his advisers would have warned against the journey, in a region which has since seen a British student killed by a polar bear.
Prince Harry took part in the Walking With The Wounded trek in April this year with a BBC two-part documentary to be aired on August 23 following his journey.
In Harry's Arctic Heroes - to be screened on BBC One - he admits: "My father obviously knew I was coming out here and so did my brother. But I kind of kept it quiet - I don't know why it happened - so my grandparents and the rest of my family probably just found out about it and they probably think I'm completely mad. It's probably right."
The expedition to the North Pole was undertaken by an unsupported team of wounded British soldiers, who covered 160 miles in 12 days with Harry joining them in the early days of the walk - less than a month before his brother William's wedding.
He also spent a short time preparing for the trek on the Norwegian island of Svalbard, the location of the polar bear attack on 17-year-old Horatio Chapple.
In the programme, Harry said the Prince Of Wales was uneasy about his participation in the walk, during which he braved temperatures of minus 45C.
He added: "My father was very nervous because of the lack of training that I've done and quite rightly so, he's got a lot of friends who have done this, he's got professional opinions that no doubt would have advised him saying 'do not let your son go'."
The royal was accompanying wounded soldiers who were injured while fighting in Afghanistan, where Harry has also served.
The soldiers were Captain Martin Hewitt, 30, from Cheshire, Captain Guy Disney, 29, from Oxford, Sergeant Stephen Young, 28, from Tonypandy, Rhondda Cynon Taf, and Private Jaco Van Gass, 26, from South Africa.
He said of his colleagues: "They've been through hell and they've come out the other side. They're doing it for all those other servicemen and women who are still coming back injured. Yes, the support's getting better, but it still needs to be so much better."