Prince Harry has lost a complaint against a British newspaper over a story describing wild animals in photographs that he posted on Instagram as "drugged and tethered."

The story, published by the Mail on Sunday in April, claimed that a series of photos taken by the Duke of Sussex and posted online to mark Earth Day were misleading, because they didn't make clear that the animals had been tranquillised.

Harry complained to the Independent Press Standards Organisation about the accuracy of the story, but the watchdog threw the case out Thursday, saying the newspaper did not breach the organisation's code of practice.

Buckingham Palace declined to comment on the decision.

According to a statement issued by the watchdog, Harry argued the full unedited photos were published on the royal family website in 2016 and have been available for anyone to see. He also said that he posted the photographs on Instagram to raise awareness -- not to show off his wildlife photography skills.

Harry argued the caption made clear that the animals were being relocated as part of conservation efforts, adding that it was not necessary to explicitly state that the animals had been sedated or tethered as this would be understood by readers.

The story in the Mail on Sunday was headlined "Drugged and tethered... what Harry didn't tell you about those awe-inspiring wildlife photos."

The article said that the elephant in the photo had been tethered and that the duke's Instagram followers would have been unable to see a rope around the elephant's legs because of the way the photo was cropped. It added that a spokesperson for Harry had declined to discuss the photos.

Prince Harry and his wife, Meghan, the Duchess of Sussex, have had a rough relationship with sections of British press ever since their relationship became public.

They spoke out against what they say is the relentless and aggressive coverage of Meghan specifically, some of which Prince Harry has described as containing "racial undertones."

The couple has launched several lawsuits against British newspapers. Last October, Meghan sued the Mail on Sunday for publishing private letters to her father, which the couple said were selectively edited. Days later Prince Harry sued the owners of The Sun and the Daily Mirror for allegedly hacking his voicemails.

In a lengthy statement at the time, Prince Harry alleged the British tabloid press was waging a campaign against Meghan that mirrored the treatment meted out to his mother, Princess Diana, who was hounded by the paparazzi until her death in 1997.

"I've seen what happens when someone I love is commoditised to the point that they are no longer treated or seen as a real person," Harry said in October. "I lost my mother and now I watch my wife falling victim to the same powerful forces."