One of the UK’s most photographed trees has been “deliberately felled” in an apparent act of vandalism, authorities have said.

The tree at Sycamore Gap, next to Hadrian’s Wall in Northumberland, was made famous when it appeared in Kevin Costner’s 1991 film Robin Hood: Prince Of Thieves.

The National Trust said it was “shocked and saddened” to confirm that the “iconic” tree had been cut down overnight after pictures emerged on Thursday morning of it lying on its side by the wall, which is a Unesco World Heritage site.

Northumbria Police said they had launched a full investigation and that “anyone found to be responsible can expect to be dealt with swiftly and appropriately”.

National Trust general manager Andrew Poad, said: “We are deeply shocked at what appears to be, an act of vandalism.

“The tree has been an important and iconic feature in the landscape for nearly 200 years and means a lot to the local community and to anyone who has visited the site.”

Alison Hawkins, who lives in Liverpool, was one of the first people on the scene this morning, posting a picture on Facebook of the felled tree with the caption: “An awful moment for all walking Hadrians wall the Sycamore Gap tree has gone! Not the storm an absolute ******* felled it!!”

Ms Hawkins, who was on her fourth day of walking Hadrian’s Wall, said she was “tearful” when she discovered the tree had been cut down.

She told the PA news agency: “At first we thought it was because of the storm but then we saw a national park ranger.

“He said it had been cut down and there was paint around the cut section, so it was a professional who knew where they were going to cut.”

“It was a proper shock. It’s basically the iconic picture that everyone wants to see.

“You can forgive nature doing it but you can’t forgive that.

“We’ve carried on the walk but news is spreading so we’ve passed quite a few people asking us if it’s true.”

The Northumberland National Park authority said: “(We) can confirm that sadly, the famous tree at Sycamore Gap has come down over night. We have reason to believe it has been deliberately felled.

“We are working with the relevant agencies and partners with an interest in this iconic North East landmark and will issue more details once they are known.”

The authority is asking the public not to visit the site, near Crag Lough, “whilst we work with our partners to identify what has happened and to make the site safe”.

A spokesperson added: “Sycamore Gap was voted English Tree of the Year in 2016 in the Woodland Trust’s awards and is much-loved by people from across the world.”

Author Amanda Marks, from Otley, Suffolk, who is staying in the area while researching for a book, told PA the act “felt like murder”.

She said: “There was a chap got there two minutes before we did from Northumberland National Park, and he was the first one to see it. And he was obviously straight on the phone saying no, this is sabotage. So somebody’s come up there, with a chainsaw, at night.

“Then people started coming and everybody’s aghast. You can’t believe it. Everybody sat there open mouthed thinking why, and who would do this?”

The Sycamore Gap tree is probably the most photographed in the country and stands in a dramatic dip in Hadrian’s Wall.

The Northumberland National Park Authority’s website says the Roman Milecastle 39 is just to its left.

Sycamore Gap is looked after by both Northumberland National Park and the National Trust.

The news was met with dismay and outrage by walkers’ groups on social media.

One Facebook user said: “I was sat crocheting at the top of the hill earlier this year while my husband and son were climbing up the rock face next to the tree. This is absolutely devastating news. It’s such a magical and magnificent place and tree. I can’t believe someone would deliberately chop this tree down.”

Another wrote on the national park authority’s Facebook page: “This is terrible news. I visit the tree regularly with my son.

“I wonder if a tree sculptor could turn the felled tree into something to remember it in its place.”

A Northumbria Police spokesperson said: “We can confirm an investigation has been launched following damage to the Sycamore Gap Tree in Northumberland.

“Inquiries are ongoing to establish whether any criminal offences have been committed.”

Tim Wickens, trustee of the Northumberland and Newcastle Society, said: “I’m truly tearful having just seen the images and reporting on the world famous tree at Sycamore gap on Hadrian’s wall apparently being deliberately felled last night.

“If it transpires this was a deliberate, it really is an outrageous and despicable act of vandalism that will shock people everywhere.

“It is beyond belief that anyone would consciously seek to destroy such a timeless symbol of the North East’s natural beauty and an icon of the Hadrian’s Wall World Heritage Site.

“I would urge anyone with useful information to contact the police immediately to help them find those responsible for this awful crime.”

Northumbria Police and Crime Commissioner Kim McGuinness, said she was “incandescent” at the news and that officers will “do their utmost to catch whoever is behind this”.

Landscape and nature author Robert Macfarlane said: “I just feel sick.

“I feel desperately sad about what it says about our wider relationship with trees and with nature in this country. And I feel very angry.”

He told BBC Radio 5 Live the tree was probably about 300 years old.

He said: “Just so many memories were stored in that tree and to see that white wood that a chain saw ripped through at some point last night. I just despair really about the state of nature in this country.”

Jack Taylor, from Woodland Trust, told the programme: “If it’s been deliberately felled, as reports suggest, it’s totally unforgiveable.”

“And, I’m really struggling to think of a reason why anybody would do that. Honestly, it would have to be a disturbed individual to do something that sort-of deliberate and heinous.”

Mr Taylor said: “We’re completely devastated that this has happened.”