It was a clear case of mistaken identity when Jackie Chan confused Prince William for his brother Harry.
The action star was introduced to the Duke of Cambridge at an evening reception at the Natural History Museum in London for the international Illegal Wildlife Trade summit.
Chan revealed that he had unwittingly congratulated the Duke on his recent trip to the South Pole with wounded veterans, only for Prince William to politely correct him, saying: "No, that was my brother."
"I said 'I'm sorry'," explained Chan, "But they look almost same, huh?"
The Prince has joined forces with Chan, footballer David Beckham and basketball star Yao Ming to film a series of short videos highlighting the illegal trade in endangered wildlife, and urging Chinese people to stop buying ivory and rhino horn.
Chan said that while Prince William was more recognisable than his father Charles, "Beckham - people will listen to him because everyone knows him."
The video shows the royal, the footballer and the action star on the pitch at Wembley Stadium, where they are surrounded by computer-generated rhinos.
The WildAid campaign video demonstrates to viewers that the world's entire rhino population could fit inside the stadium, but their numbers could be increased by stopping the demand for rhino horn.
In the message, Prince William says: "Together we can save our wild rhinos. When the buying stops, the killing can too."
Beckham adds: "Ask your friends and family never to buy rhino horn."
In another video, Chan warns viewers that buying rhino horn supports the dark side of the trade.
"You're paying for guns, bullets, poisoned arrows, chainsaws, axes, and machetes to hack off the face of the rhino. And you are paying for the life of a beautiful creature."
Speaking at the reception, Prince William presented a five-point plan to help safeguard endangered animals like rhinos, elephants and tigers as world leaders prepare to meet to discuss the issue.
"Tonight we are here with a single, shared purpose - to use our collective influence to put a stop to the illegal killing and trafficking of some of our world's most iconic and endangered species," he said.
"Never before has a group like this come together - in these numbers - to stop the illegal trade in wildlife. All of us in this room have a duty to make sure that tomorrow, 13th February, is a date that marks the beginning of the end of this despicable trade.
"'The conference will bring together leaders from around the world who will pledge to reduce both the supply and the demand driving this trade.
"Let's not for a second underestimate how important this step is.'
The Rush Hour 2 star said that the use of animal parts as health remedies is a common practice for Chinese households.
He said that on learning of the way in which tigers, elephants and rhinos were killed for the products, he became involved in the efforts to stop the trade.
"This why I wanted to be a spokesperson against the animal trade, it's my duty to tell the Asian world, the people who believe these kind of things - its wrong."
In a major international summit held yesterday, ( 13 February) leaders and representatives of 46 countries made a pledge to tackle poaching.