When the film was developed the photographs showed the face of at least one suspect while another is seen drawing graffiti on the wall.

Police believe the vandals intended to steal the camera after causing damage estimated at about £2,000 at Wicor Primary School in Porchester, Hampshire.

A spokesman for Hampshire Constabulary said: "The only thing we can imagine is they decided to take photographs of themselves and apparently mistakenly left the camera behind."

The break-in is believed to have taken place between Friday evening and Monday morning.

The intruders damaged a £1,000 computer by pouring paint into it and also splashed paint across the classroom, as well as damaging a £300 guitar, a CD player costing £100 and a carpet costing £200.

The photographs were developed by the head teacher of the school, Mark Wildman, who discovered the camera after the burglary.

Mr Wildman said he could not understand why the vandals had taken photographs of themselves.

'Daft enough'

He said: "It is quite bizarre. The teacher whose camera it was thought it had been stolen but then we found it in another classroom under a pile of purple paint.

"She said `I wonder if they were daft enough to take their own pictures'.

"We laughed and said don't be so silly but lo and behold here was this face on the photograph which she didn't recognise with the classroom in the background.

"We are all asking ourselves why. It was sheer mindless vandalism. It's just hard to understand what motivates someone to do this," said Mr Wildman.