David Cameron has described Nigeria and Afghanistan as "fantastically corrupt" in a conversation with the Queen.
The PM was talking about this week's anti-corruption summit in London."We've got some leaders of some fantastically corrupt countries coming to Britain... Nigeria and Afghanistan, possibly the two most corrupt countries in the world," he was overheard saying.
Nigerian President Muhammadu Buhari, elected last year after vowing to fight corruption, said he was "shocked".
And a senior Afghan official said the characterization was "unfair".
After Mr Cameron's comments, Archbishop of Canterbury Justin Welby intervened to say: "But this particular president is not corrupt... he's trying very hard," before Speaker John Bercow said: "They are coming at their own expense, one assumes?"
The prime minister's remarks were outspoken and unguarded but they were not untrue. Both Afghanistan and Nigeria come high on lists of the world's most corrupt nations.
And later in the conversation, the prime minister agreed with the Archbishop of Canterbury that President Buhari of Nigeria is not corrupt himself and is trying very hard to tackle the problem.
In response, Mr Buhari said his government was deeply "shocked and embarrassed" by the PM's comments. Speaking through his spokesman, he suggested that Mr Cameron must be referring to Nigeria's past notoriety for corruption before his coming to power last year.