Woman unknowingly pays for Keith Urban's petrol

New Zealand-born country music star Keith Urban needed rescuing at a New Jersey petrol station when he realised he was short a few dollars.

When she heard another customer ask the woman with him if she had any money, local grandmother Ruth Reed jumped at the chance to help someone out and handed him the cash he needed.

The retired teacher didn't realise he was the multi Grammy award-winning musician, who has a net worth of US$75 million (NZ$111 million).

In a Facebook post, she said he introduced himself to her only as Keith and thanked her for helping her out. She then remarked to his face how much he resembled the famous singer.

That's when he revealed that he was in fact Keith Urban.

Mrs Reed says she didn't believe him at first, and asked where his wife Nicole Kidman was. She only believed it was him when she received confirmation from his bodyguard.

Urban was grateful to her for her generosity, and took a photo with her to say thanks.

The singer was in town for a concert touring his latest album Graffiti U.

Newshub.