POLICE are investigating threats issued against men who carry out the ancient but controversial annual slaughter of baby gannets for food in the Outer Hebrides.

It is the only hunt in the UK where guga – baby gannets – can be killed for food and around 2,000 are harvested on Sula Sgeir, a small island about 40 miles north of Ness on Lewis, in August.

Now it has been claimed that the threats were related to a group of 10 hunters who spent a fortnight on the rocky outcrop.

A series of anonymous phone calls were reportedly made to people in the area from telephone numbers which are understood to have originated in the south of England.

The men were due back home on Wednesday night with their haul, which are prized in the local area as a culinary delicacy, with each individual bird fetching around £13.

A police investigation has now been launched into the source of the threatening phone calls.

A spokesman for the force said: “We have received a complaint and our enquiries are ongoing.”

The Ness community newspaper, Fios, also reported receiving a call threatening the guga hunters, stating “the murder had to stop.”

According to a report commissioned by Scottish Natural Heritage last year the guga hunt is not affecting the bird’s numbers. SNH said the research demonstrated that the birds were “faring fairly well” on the isle.

It said the study also suggested the harvest was sustainable long term.

Animal welfare charity the Scottish SPCA and campaigns organisation Care2 have opposed the harvest.

But SNH said: “We recognise the importance and cultural significance of the guga hunt. Indeed the provision to license it through the Wildlife and Countryside Act reflects this.

“The survey data we have demonstrates that northern gannets are faring fairly well on Sula Sgeir.

“The count data available to us give us reassurance that the annual harvest of 2,000 gugas appears to be sustainable.”

The hunting of sea birds was outlawed in 1954 in the UK but the Ness community continue to be granted the only exemption under UK and EU law allowing them to hold the annual hunt. A petition calling for a ban on the killing of guga in 2014 attracted more than74,000 supporters.

The controversial centuries-old hunt involves the birds being clubbed to death.

The Scottish Government has said it is satisfied the methods used to kill the birds are not inhumane if done competently. The RSPB has also not raised objections.

For at least 500 years men from Ness have travelled to the remote uninhabited rock with the first recorded trip being in 1549.

The men live on the island for two weeks, sleeping among ruins left behind by monks over a thousand years ago.

They work ceaselessly, catching, killing and processing 2000 birds using traditional methods unique to the hunt.

The birds are slain with a stick – the hunters say death is quick and humane – decapitated, singed in fire and pickled in salt.

The Ness community paper, Fios, also reported receiving a call threatening the guga hunters.

It said: “The man, who is believed to have had a Midlands or northern English accent, went on to say that he spoke for a higher power and wanted to pass on a message to the men in the boat, essentially threatening them and the journalist if the message was not relayed to them.

“A check revealed that the call had originated from a payphone in Bournemouth.”

“There is always some sensitivity surrounding the annual guga hunt, despite agencies such as SNH not expressing significant concerns about the age-old and uniquely Niseach culinary tradition, with gannet numbers on Sulasgeir described at present as ‘healthy’.”

Western Isles MP Angus Macneil said: “They won’t stop what is the last ancient bird fowling tradition left in the British Isles.”