The 51-year-old man, who is also known as Jester, was reported missing after last being seen at 18:30 on Monday 8 July as he left his home on Rue De Bouverie, Castel.
Detective Sergeant Andy Telford today said there have been no confirmed sightings of Mr Giles since then.
Searches are continuing, he said, with the case now handed over to detectives in the Guernsey Police Public Protection Unit.
Officers have carried out a number of searches across the island as well as reviewing CCTV and speaking to witnesses.
DS Telford said it’s possible Mr Giles was wearing was a blue rain jacket with a SkyTV logo on the front when he left his home.
He’s urged anyone who sees Mr Giles to contact police, and he also asked Mr Giles himself to get in touch with officers.
The police searches began early Tuesday morning and are continuing.
New images of Mr Giles have been issued by police on social media. They are shared above.
Anyone with information is asked to call 01481 222222.