A honourable passer-by who found a diamond ring outside a Nando’s has returned it to its owner in what he described as ‘a fairytale ending’.

The finder, Andy, saw the ring's massive stones sparkling on the floor and instead of ‘flogging it’, decided to do the honourable thing and try to find the owner.

He launched a Facebook campaign to find the owner of the ring, and today he met up with the lady who it belonged to and returned it to her.

Andy said: ‘It’s a fairytale ending and shows just how much good social media can do. I feel like I have done my good deed for the year.’

Andy, 31, a consultant, was contacted by the owner earlier today. He got a taxi to meet her at a London jeweler and staff verified insurance records she held for the ring that proved it belonged to her.

Andy has no idea what the ring is worth but an independent jeweler who saw pictures of the ring on social media said the main stone was as big as 3.5 carats. 

Sarah Sheard, manager of Hatton Jewels Ltd in London, said she thought the central stone is three to three and a half carat, although said she could not be sure what stone it is from pictures alone.

Mrs Sheard said that the mount was platinum and the stones in it could be around two carat.

But despite the size of the huge stone, Andy decided to try and give it back after having similar experiences with other good willed people returning his lost phone.

Andy added: 'She was overjoyed because she had been upset and doesn’t want any attention, but she was very, very pleased to have it back.'