Mystery surrounds the disappearance of a six-foot sculpture of a Celtic sea god from a mountainside.
Manannán Mac Lir, which is made out of fibre glass and stainless steel, was stolen from Binevenagh Mountain near Limavady in County Londonderry.
The statue had became a popular tourist attraction in the area since its installation about a year ago.
Sculptor John Sutton, who has worked on the award-winning Game of Thrones series, has spoken of his shock.
He said it would have taken a number of men with angle grinders several hours to remove the figure from its base.
"I'm very disturbed by this," Mr Sutton said. "It's unreal.
"Some statues are stolen for their bronze. But this was cut down at the base and the materials would not have been worth stealing.
"I made it out of clay first and then a silicone mould, before I cast it. It took me months and months to make and five or six men to carry it up there and install it.
"It was very heavy and would have taken a long time to remove."
Manannán Mac Lir is a sea deity in Irish mythology and is also said to have been the first ruler of the Isle of Man.
Manand is the old Irish name for the Isle of Man and as his surname suggests, he was the son of Lir, meaning sea.
People in the Limavady area tell of the presence of a sea god in Lough Foyle, County Londonderry, and the widespread practice of making offerings to deities in Celtic times.
Those who made off with the sea god left a wooden cross with the words 'You shall have no other gods before me' in its place.
Mr Sutton's £10,000 creation overlooked Benone Beach, Magilligan, Limavady and Donegal and was part of Limavady's sculpture trail.
"I was very proud of this. It was very popular with photographers," he said.
According to Limavady Borough Council's website, people in the area believe that the spirit of Manannán Mac Lir at Gortmore Viewing Point is released during fierce storms.
Some elderly folk in the area are still heard to remark "Manannán is angry today," when the River Foyle is rough and refer to the angry waves as "Manannán's seahorses."
According to mythology, Manannán had many magical possessions.
He had a horse that could travel over land and sea and owned a metal boat, which obeyed the thoughts of its sailors.
The police said they were notified of the theft at about 10:25 GMT on Wednesday.
"This statue of Manannán Mac Lir was in the area of Gortmore viewing point and is part of the Myths and Legends sculpture trail," Constable Nelson said.
"Anyone with any information about this theft is asked to contact Limavady police station on the non-emergency number 101."