Concerns have been raised after people were seen on a webcam apparently interfering with puffin burrows at Sumburgh Head late on Monday night.
Viewers of the popular ‘puffin cam’ appeared to see a couple of people with torches climb over the wall at the Sumburgh lighthouse towards the nesting birds.
A third person was also seemingly captured on camera staying put behind the wall.
Voices could be heard on the webcam footage as the individuals were just metres away from audio recording equipment.
The incident happened at around 11pm.
The RSPB is aware of the footage, while local police are keen to hear from anyone with information about the identity of the people and their intentions.
Officers also reminded people that tampering with birds can be an offence.
All wild birds in Great Britain are protected under the Wildlife and Countryside Act.
Andy Steven, who runs the Shetland Webcams website, said he watched the incident live and checked with the RSPB to see if there was anything “official” happening.
“The activity did look planned and suspicious with three people involved,” he said.
“They did not appear to realise they were being streamed live and they were tampering with the puffin burrows just a few metres from our sound recording head, so their voices were captured too.”
Last month,, conservationists asked the public to get snap happy with puffins – so they can find out their eating habits.
The Royal Society for the Protection of Birds (RSPB) launched its annual Puffarazzi project in May.
Visitors to puffin colonies around the UK and Ireland – including Lunga off Mull, Noss in Shetland and Fair Isle – in spring and summer this year and next are asked to join the Puffarazzi by photographing these colourful seabirds with fish in their bills.
The project is now also asking for historical photos to be submitted to aid conservation efforts.
All these images will help scientists learn more about what puffins are feeding their chicks, known as pufflings.
Puffins as a species are now classed as vulnerable to extinction.