Police are investigating a "horrendous" wildlife crime on a protected osprey nest after vandals used a chainsaw to destroy the site.
Conservationists have condemned the attack at Llyn Brenig Lake in Wales as “senseless, cruel and wanton”.
The culprits are suspected to have arrived by boat on Friday evening before cutting down the artificial nesting platform.
In CCTV footage of the incident, a loud chainsaw can be clearly heard in the background as the nest shakes before toppling and crashing into the lake.
The first egg of the breeding season, which had been laid in the nest just hours before the attack, was destroyed in the fall.
Destruction of an osprey site in this manner carries a six month prison sentence and a £5,000 fine, North Wales Rural Police said.
There are just five pairs of ospreys in Wales with the birds and eggs protected under the Wildlife & Countryside Act.
Officers believe the criminals had a ‘strong motivation’ to drive the ospreys away from the area yet declined to provide further details.
Sgt Rob Taylor, of North Wales Police Rural Crime Team, said a thorough investigation is underway to find those responsible for the "disgusting" act.
He said: "We really are pulling out all the stops to try and catch the person or persons responsible for this and believe me they will receive the full force of the law if we do catch them."
"The whole team is absolutely devastated by it and sure the whole community is as well.
Although motivations behind the attack remain unclear, theories posited online suggest it could have been carried out by fishermen attempting to permanently drive the birds of prey away from the site.
The lake, which is home to rainbow trout, has hosted World, Commonwealth and International matches of competitive angling.
However, officials at Welsh Water, which manages the site, and North Wales Wildlife Trust have vehemently denied any suggestion it could be related to fishing, describing it as "unthinkable".
Graeme Cotterill, of North Wales Wildlife Trust, said: “This is a horrendous wildlife crime that's happened here at Llyn Brenig.
"We appeal to all members of the public if you know anything at all about what happened here please do report it to the police using the crime number on our website.
"These are the rarest birds in Wales and there are very few breeding nests.”
Two members of the public , Alan Davies and Brian Iddon are offering a £2,000 reward for information leading to a successful prosecution of the criminals that destroyed the nest.