A 65-year-old man thought to be sleeping while sitting upright on a Berlin underground train as it crossed the German capital was actually dead.

A Berlin police spokeswoman said: "It's tragic. We don't know how long he was sitting dead on the train, nor do we know the exact cause of death yet.

"There are no indications of foul play. He seems to have died of natural causes."

The man was found dead at 5.45am when a rail worker tried to wake him up by gently shaking him.

Medics were called in but could only pronounce the man dead.

A preliminary investigation showed no indications of the man being murdered.

A more detailed examination is planned for tomorrow.