French President Nicolas Sarkozy has posted on Facebook a picture of himself at the Berlin Wall, saying he had chipped away at it with a pickaxe.

The image shows Mr Sarkozy, then a 34-year-old French MP, standing before a graffiti-covered section of the wall.

His caption dates the image to 9 November 1989, but French observers say it was probably taken the next day.

In the caption, the French president says he arrived in West Berlin with a group of French politicians on the morning of 9 November, crossed Checkpoint Charlie to the East, and headed for the Brandenburg gates.

However, French commentators point to a possible mix-up of the dates.

They say news of the collapse did not come until late in the day on 9 November, and West Berliners did not begin attacking the Wall until the following day.