US President Barack Obama repeatedly called British finance minister George Osborne "Jeffrey" at the G8 summit, media reported on Thursday.
The US president said three times that he agreed fully with "Jeffrey" during his presentation on G8 host Britain's plans to crack down on tax avoidance, leaving Osborne red-faced.
Realising his blunder afterwards, Obama joked that he had mistaken Britain's chancellor for the US soul singer Jeffrey Osborne, The Sun and the Financial Times reported.
"I'm sorry, man. I must have confused you with my favourite R and B singer," Obama was quoted as saying.
The chancellor, 42, bears little resemblance to Jeffrey Osborne, a 65-year-old African-American hit singer-songwriter known for his 1982 classic On the Wings of Love.
Jeffrey Osborne told Sky News television: "I was really delighted actually. I was really not aware that (Obama) was that much of a fan that he would call the chancellor Jeffrey Osborne.
"Tell the chancellor when I come over I will have to hook up with him and we will do a duet of 'On The Wings Of Love'."
The Sun quoted an onlooker at the session as saying: "Osborne looked really put out" by what was a "visually crushing blow".
"The first time Obama did it was bad enough, but then he kept on repeating the error throughout the presentation. It got really cringe-worthy by the end."
George Osborne's real first name is Gideon, but he switched to George after being teased as a teenager.