A "dramatised documentary" based on what would happen if Prince Harry were to be taken prisoner while serving in Afghanistan has been criticised as "deeply distasteful".
The Taking Of Prince Harry features contributions from former hostages and intelligence experts and includes scenes where the prince, played by Sebastian Reid, is held behind enemy lines while negotiations are carried out to free him.
A defence source said: "The depiction, fictional or otherwise, of a member of the Armed Forces being taken hostage and mistreated is deeply distasteful."
At one point Harry is shown having an unloaded gun pointed in his face before one of his captors pulls the trigger, and he is also made to appear in Taliban and al Qaida propaganda.
The 90-minute film, to be broadcast on October 21 at 9pm, also includes scenes where the Prince is confronted by a British-born radical Islamist and details how the British Government's approach to hostage negotiations differs from other nations.
Harry, younger son of the Prince of Wales, served in Afghanistan's Helmand province but was flown home in February 2008 when the secret was leaked.
His presence in the country was hush-hush because of worries he could become a Taliban target if it became widely known he had been deployed.
Channel 4's head of documentaries, Hamish Mykura, said the broadcaster had informed Buckingham Palace about the film, but had not had any response.
He said he did not think making the film increased the risk of potential high-profile kidnappings, adding: "I think it is just wrong to say that this would create a new idea that wasn't there already."
A Clarence House spokesman said Harry's reaction to the programme was "private" and added: "Speculating about the security of Prince Harry, both as a serving member of the Armed Forces and a senior member of the Royal Family, is unhelpful."