Police are appealing for a missing Kettering man to make contact with them.
Derek Witten, 77, has not been seen for more than a month and officers are increasingly concerned for his welfare.
Mr Witten is vulnerable and it is believed he may have travelled to London at some point in the last four weeks.
He is white, 5ft 4ins and of medium build, with short grey hair.
Mr Witten, or anyone who knows of his whereabouts, is asked to contact police on 101 or Crimestoppers anonymously on 0800 555111.