A prisoner on the run walks into a bar and orders a glass of water.

There's no alcohol in water, but he still blabbed he had escaped from prison to the barman, who promptly rang police and the man was arrested shortly after.

The incident happened in Lower Hutt on Thursday night and while the barman thought the story was too good to be true he called police anyway, Acting Inspector Bruce McKay told Radio New Zealand.

"It turns out that, yes, he was overdue from a local prison, so that's where he'll be going back too I'd imagine," Insp McKay said.

The man was discovered to be driving a stolen car and was picked up not long after driving away from the bar.