Footage has emerged showing North Korean ruler Kim Jong-un's elder brother in London - attending two Eric Clapton concerts.
Two different videos show Kim Jong-chol visiting the Royal Albert Hall on successive days.
He has previously been seen attending Clapton concerts abroad.
One North Korea observer confirmed the man in the footage was Mr Kim, who was taken out of the leadership succession several years ago.
Video filmed by a Japanese television network on Thursday shows a car arriving outside the venue in west London, and a woman wearing a green leather jacket and sunglasses emerging from inside.
Cameras follow her briefly before Mr Kim, dressed in almost identical clothes, also walks out of the car.
He is asked a number of questions by journalists but does not speak. Several minders surround him, and they push journalists and cameras away from the man.
The same visitors were also seen at a Clapton concert in the same venue on Wednesday night.
Simeon Paterson, a BBC journalist who attended Thursday's concert, said: "He was just like any other fan, but there were officials all around him.
"They were obviously not Clapton fans, and looked really out of place. But he was having a great time, singing along to all the words."
Kim Jong-chol has attended Eric Clapton concerts in Germany in 2006 and Singapore in 2011.
Mike Madden, who runs the North Korea Leadership blog, said he could confirm it was Kim Jong-chol. Mr Madden said he had been told members of the Kim family were travelling to the West in May.
Mr Madden said one man who holds Mr Kim's arm in Wednesday's video was a trusted aide to the Kim family. "He knows everything that the Kim family is up to at all hours of the day - an important man," said Mr Madden.
He added that Mr Kim and his aides were likely to have been travelling on diplomatic visas issued by the North Korean embassy in London, or on passports from other countries.
The South Korean news agency Yonhap said (in Korean) that Kim Jong-chol stayed at the Chelsea Harbour Hotel in west London, where rooms can cost more than £2,100 ($3,290) a night. The hotel did not respond to the BBC's requests for a comment.
He had been due to board a flight to Moscow on Friday, Yonhap said.
According to the North Korean Leadership blog, Kim Jong-chol is the oldest child of the fourth wife of former ruler Kim Jong-il, and is 33 years old.
It says that, like his full brother Kim Jong-un, he was educated in Switzerland before returning to North Korea.
Kim Jong-il's former sushi chef said the former ruler saw his son as being "no good because he is like a little girl."
Kim Jong-chol had at one point been considered for the North Korean leadership, but was overlooked by his father in 2009. Kim Jong-un eventually took over when his father died in December 2011.
The North Korean Leadership blog says that Kim Jong-chol has "a pleasant, outgoing personality" and plays an important support role for his brother. At one point, he worked in North Korea's propaganda department.