Officers are growing increasingly concerned for the safety and wellbeing of 74-year-old, Alister Daniels, who was reported missing when he did not return after leaving his home in Trimmer Walk, Brentford at around 11am on March 1.
The pensioner, who suffers from a number of serious medical issues, was last seen leaving Queen Alexandria Hospital in Portsmouth, Hampshire at around 5.45am on Thursday March 2, according to officers.
When he was last seen, he was wearing a blue coloured parker, black trousers and white trainers.
Mr Daniels is described as around 5ft 7ins tall and of frail build, he is white, with short grey hair and has a thin white moustache.
The 74-year-old could be travelling back to London, or anywhere else from Portsmouth, as he has access to public transport with his Freedom pass.
Police are urging anyone with information relating to his whereabouts, to contact them on 101.
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