James Corden was "kidnapped" by 'Carpool Karaoke' fans in London recently.

Speaking to The Wrap, James said: "I was crossing the street in London a few weeks ago and there were these four kids. They were like 18, 19. They sort of forced me to get in the car. They all had their camera phones out and we were just singing along to the radio. I was like, 'Am I being kidnapped?'"

'Carpool Karaoke' has featured celebrities including Adele, One Direction, Mariah Carey and First Lady Michelle Obama and James admitted its success is "madness" to him.

He told Variety: "On our first show we did this bit with Tom Hanks where we recapped his film career in seven minutes, and that’s been viewed 18 million times on YouTube. Then, the next night, we put out 'Carpool Karaoke'. Who could have ever predicted that that would become just this thing where millions of people would just watch these segments. It’s madness to us."

And James revealed one of the most memorable 'Carpool Karaoke' segments he did involved the Red Hot Chili Peppers.

He said: "They were so free in their discussion, and they were so open, and they had no care or time for thinking, 'Oh, how are people going to perceive it?' It was just they were exactly who they were, from start to finish, and I have to say the truth is I just found being in their company completely thrilling."