Prince Harry has been accused of war crimes by the Iranian regime after boasting about the number of Taliban fighters he killed in Afghanistan in his recently released book.
Iranian officials slammed him on social media amid a bitter diplomatic row with the UK government over the execution of a British national by Tehran.
Prince Harry claimed in his autobiography Spare that he killed 25 Taliban fighters while serving for the British Army in Afghanistan.
The royal said he thought of those he killed as "chess pieces", rather than people, sparking outrage.
Harry said he thought of those he killed as "chess pieces", rather than people, triggering outcry from British veterans and Taliban officials.
Iran's foreign ministry tweeted: "The British regime, whose Royal Family member sees the killing of 25 innocent people as removal of chess pieces and has no regrets over the issue, and those who turn a blind eye to this war crime, are in no position to preach others on human rights."
Prince Harry's comments prompted a sharp backlash from members of the military community, with leading figures saying they could jeopardise his safety and give the British Army a bad reputation.
The claims by Iranian officials come amid after the regime executed dual Iranian-British national Ali Reza Akbari, a former senior defence ministry official, for spying.
The execution further escalated tensions with the West amid the nationwide anti-government protests shaking the Islamic Republic.
UK Prime Minister Rishi Sunak slammed his execution.
"This was a callous and cowardly act, carried out by a barbaric regime with no respect for the human rights of their own people," he said.
Prince Harry served in the British Army for 10 years. He completed two tours of Afghanistan, one spanning 2007 to 2008 and the other from 2012 to 2013.
He achieved the rank of captain in 2011 and qualified as an Apache Aircraft commander. Captain Harry Wales, as he was known in the Army, retired from the service in 2015.