A man visiting a London branch of Waterstones bookstore was trapped inside the building for hours on Thursday night after staff locked up the store for the evening without realising he was still inside.

Despite popping in just to use the wi-fi, David Willis got far more than he bargained for when he walked into the Trafalgar Square branch shortly before 9pm.

David did not notice staff turn off the lights and lock up two floors below and told Good Morning Britain how he realised what had happened far too late:

I was using the internet for 10 or 15 minutes and all the lights were on upstairs. David Willis

He spent hours alone in the empty bookstore, but not before posting an appeal to be freed on Twitter and showing the conditions of his confinement on Instagram:

Happily, staff eventually arrived to free the Texan native, who tweeted news of his release in the early hours of Friday:

Willis, who experienced more enjoyable trips to tourist spots in Italy earlier this week, at least saw his posts retweeted more than 6,000 times.

Waterstones also confirmed that it had freed its customer: