A prominent former British Army officer from Kent has branded Prince Harry's revelations about how many people he killed as a soldier a "tragic money-making scam".

Col Tim Collins, who lives in Canterbury, has hit out at the royal for writing in his new memoir that he was responsible for a death toll of 25 in Afghanistan.

In the book - titled Spare - Harry says he did not think of those he killed as "people", but instead as "chess pieces" that had been taken off the board.

On how many lives he took, he writes: "So, my number is 25. It’s not a number that fills me with satisfaction, but nor does it embarrass me."

Col Collins, who became a household name in the Iraq War 20 years ago, told Force News the prince "has badly let the side down".

The retired soldier, who had been commander of the 1st Battalion Royal Irish Regiment based at Howe Barracks in Canterbury, said: "Prince Harry's latest revelations are clearly a tragic money-making scam to fund the lifestyle he can't afford and someone else has chosen.

"Amongst his assertions is a claim that he killed 25 people in Afghanistan. That's not how you behave in the Army; it's not how we think. He has badly let the side down. We don't do notches on the rifle butt. We never did.

"The British Army was deployed to Afghanistan to assist the lawful government and the benighted people – not to kill them."

Col Collins is widely known for his eve-of-battle speech to troops ahead of the invasion of Iraq in March 2003. The country was then in the grip of dictator Saddam Hussein.

He famously said: "We go to Iraq to liberate not to conquer. If you are ferocious in battle remember to be magnanimous in victory."

Today he spoke of the lives lost during the war in the wake of Harry's comments.

"We lost people and insurgents also died – as did some innocents caught in the conflict," he said. "But that was a regrettable consequence of a lawful intervention with the best intentions.

"Harry has now turned against the other family, the military, that once embraced him, having trashed his birth family.

"I wonder whose path he has chosen? In the end, I see only disappointment and misery in his pursuit of riches he does not need and his rejection of family and comradely love that he badly needs."

Others who have condemned the Prince include Anas Haqqani, the Taliban leader in Afghanistan.

He tweeted: "Mr Harry! The ones you killed were not chess pieces, they were humans; they had families who were waiting for their return.

But he added: “Among the killers of Afghans, not many have your decency to reveal their conscience and confess to their war crimes."

Prince Harry served in the Army for 10 years until 2015, undertaking two tours of duty in Afghanistan and ending up at the rank of Captain.

His autobiography is due for publication next Tuesday but by mistake went on sale in Spain beforehand.

Harry says in the book that flying six missions during his second tour of duty on the front line in 2012 to 2013 resulted in “the taking of human lives”, of which he was neither proud nor ashamed.

The prince was criticised in early 2013 at the end of his tour when he disclosed that he had killed.

He then told the media that he took the enemy “out of the game” and soldiers “take a life to save a life”.

Prince Harry, now 38, moved to America after falling out with others within the Royal Family. In the book he also claims brother Prince William once grabbed him and knocked him over during a row.