A man has been arrested on suspicion of kidnap after a vulnerable pensioner went missing nearly three weeks ago.
Timothy Hatcher, 69, was last seen on 18 December at a Co-op store in Chelmsford in Essex.
Mr Hatcher, who has dementia and receives support from carers, was reported missing two days later.
A 50-year-old man was arrested on suspicion of kidnap, according to Essex Police. He has since been released on bail.
Detective Superintendent Scott Egerton, who is overseeing the investigation, said that police are "incredibly concerned" for Mr Hatcher's welfare.
"We have a team of officers working round the clock in order to piece together Timothy's known movements, including aspects of his financial life and his phone use.
"Unfortunately, at this stage he remains missing and we continue to focus a great deal of effort in trying to locate him."
Det Supt Egerton appealed to the public for information.
"The eyes and ears of the public are incredibly important to this investigation and I would urge anyone who believes they could have information on Timothy's whereabouts - no matter how small that is - to please contact us."