A memorial would not normally be regarded as the right place to pose for a ‘selfie’.

But a grinning David Cameron and Barack Obama did just that during the memorial for Nelson Mandela.

The two leaders squeezed up as Danish Prime Minister Helle Thorning-Schmidt took the snap on her camera phone.

Within minutes the photograph of the three leaders posing for the ‘selfie’ went viral on the internet, staking its claim to become the most famous - if controversial - taken so far.

Unsurprisingly, opinion was divided as to whether it was appropriate behaviour at an event to mark the passing of the anti-apartheid hero who died last week aged 95.

Some Twitter users were unimpressed by the light-hearted way the two PMs and the President had conducted themselves.

One person posted: “What selfish morons take a ‘selfie’ at a memorial service? Oh yeah that’s right, Barack Obama and David Cameron.”

In a message directed at Mr Cameron, Sarah McDermott, using the Twitter name @toxicsayonara, said: “You have precisely zero class or decorum.”

The Mirror’s Facebook page was also inundated with comments. Angie George said it was “dreadful behaviour by world leaders at a memorial service. Everyone of them should hang their heads.”

While Cassandra Brightwell wrote: “Shocking behaviour from 2 of the most important men in the world lets see when it comes to their memorial services.”

But one reader commented: “Well the memorial show on BBC this morning was boring.”

Others argued it was in keeping with the event at the FNB Stadium in Soweto where tens of thousands of South Africans danced and sang in celebration of the man they called Madiba.