It is four weeks since the 64-year-old went missing. He was last seen within an address in Panbrae Road, Bo’ness at around 11.30pm on Thursday, July 6.
He left the property at some point during the night and has not been seen since before being reported missing to police on the morning of Friday, July 7.
Arnold is described as white man with a slim build, blue coloured eyes and dark receding hair. He is around 6ft 3in and has a North Scotland (Shetland) accent.
He is believed to be wearing blue trainers, but the rest of his clothing is unknown. He has previously lived in the Aberdeen and Shetland areas.
In the last four weeks officers have conducted an extensive search to trace Arnold and several specialist resources have been deployed to both the Bo’ness and wider area.
Search and rescue officers have also been deployed along with police dogs, whilst the Police Scotland Marine Unit has used specialist equipment in the water near Bo’ness.
Officers are still conducting searches of the local and wider areas, which they say will continue for the foreseeable future. Police would like to thank those members of the public who have assisted officers to date in our search for Arnold.
Inspector Martin Rutland, Community Inspector for the Bo’ness area, said: “Our search for Arnold is ongoing and we are still activity looking to trace him.
“I would like to pay tribute to Arnold’s family for their support throughout this time. I would also like to thank the public and media for their assistance throughout this investigation, the response to our appeal has been overwhelming.
“Unfortunately, we are still looking for that key piece of information that will give us the answers that Arnold’s family are desperately seeking.
“I would again ask anyone who remembers seeing Arnold in the Bo’ness area either on the night of Thursday, July 6, or the early morning of Friday, July 7,or recognises his description to come forward. That piece of information may be vital and may be what leads us to tracing Arnold.”
A media campaign has been launched along with a poster, which was distributed across the local area. Over 50 volunteers also participated in various searches in order to assist police efforts.
Anyone with information on Arnold’s whereabouts is asked to contact officers at Grangemouth Police Station on 101, quoting incident number 1022 of July 7.