Pensioner John Reynolds was in good spirits this afternoon as he returned home to North Walsham following the large scale search relayed across the world via the social networking sites Facebook and Twitter, which ultimately led to his discovery.

The 81-year-old was kept in overnight at Norfolk and Norwich University Hospital's (NNUH) Cringleford ward for observation reasons following blood tests, but was allowed to return home earlier today.

His family spoke of the important role played by Facebook in helping to track him down when he failed to return to the hospital after going for a walk at 1pm on Monday.

An appeal put out through the website was shared 22,500 times and was seen by Old Catton man Jake Beales, 23, who recognised Mr Reynolds while walking his black Labrador Zooskie in George Hill, more than six miles away from the hospital.

Mr Reynolds' daughter Natalie Wade said: 'The Facebook campaign actually led to him being found so I was very impressed, especially by the number of messages being shared- the appeal was shared 22,500 times.

'I think that is the best use of Facebook. I have been critical of it in the past, but the fact that it led to someone recognising him proves that it works.'

His son Rich Greeves posted: '22,000 reposts of my appeal for my dad. I am blown away by the kindness and support in Norfolk tonight. Wait till I tell him what a celebrity he is thank you one and all.'

Ms Wade said her father was happy to be returning to the home he shared with his wife Rosalind after being discharged, adding: 'He was in good spirits when he was found and he enjoyed having the attention of three nurses and was very happy to be staying in the hospital overnight.'

The family also raised some concerns about the care he received at the hospital, feeling he should not have been left unattended as he had a medical condition.

A spokesman for the hospital could not comment on Mr Reynolds' circumstances, but said patients were assessed to see if they needed more intensive nursing observation.