The bird was captured on camera by photographers on Howden Moor, near Sheffield, on Sunday morning, with the species having only been seen once before in the UK in 2016.
It is thought to have come from the French Alps, where a population was reintroduced in the 1980s after being hunted to extinction by the early 20th century.
Yet the juvenile is roosting close to the grouse moors of the Dark Peak, which is one of the country's hotspots for the persecution of raptors that feed on game birds reared on commercial shooting estates.
The Derbyshire Wildlife Trust, who are monitoring the vulture, fear that it could be trapped or killed by gamekeepers ahead of the start of the shooting season on August 12.
There are only 600 breeding pairs remaining in Europe, with the population extending as far east as the Ural Mountains.
Howden Moor, where the vulture has been roosting, is protected moorland owned by the National Trust.
Yet is has been seen flying over Sheffield, Edale, Castleton, Chatsworth and parts of the West Midlands, and was tracked over Belgium before it crossed the North Sea on what is thought to be an exploratory trip away from the Alps, where it is likely to return to find a mate.
It is one of the biggest wild birds ever seen in the UK.
But Tim Birch from the Derbyshire Wildlife Trust told The Times that there could be 'international consequences' for anyone who harmed the endangered bird, which also roams in Africa and the Indian subcontinent.
He acknowledged that the 'threatened' bird was living in a notorious hotspot for bird of prey persecution close to the beginning of the grouse season, and said there would be 'repercussions at international level' if it was killed.
A buzzard was shot dead in the Peak District last month and the Dark Peak has been described as a 'black hole' for birds of prey by wildlife charities, with species such as goshawk and peregrine falcon, which would normally live on the moors, almost extinct locally.
Hundreds of birdwatchers have travelled from all over the country to try and catch a glimpse of the vulture.
“It’s a truly magnificent sight, to see Britain’s largest bird of prey in Yorkshire, and hundreds of birders from all over the country have made the journey,” William Bowell, a retail manager who watches and photographs birds as a hobby, told the PA news agency.
Mr Bowell said the bird was tracked through the West Midlands and Derbyshire, but nobody had “pinned it down” until the weekend.
He said he was told of the bearded vulture’s location by another birdwatcher, then walked for two hours to get to the remote location.
“He spotted it on Friday night so I went down on Saturday morning. I missed it by about 20 minutes, and went back on Sunday morning. I left home at half three in the morning,” Mr Bowell, who lives in south Lincolnshire, told PA.
“They were sublime views, I just never expected it. When we got there after missing it on Saturday it was elation.
“I never expected to get anything like those views, it was mind-blowing. Quite unexpected and quite remarkable.”
Mr Bowell said he will not attempt to photograph the bird again while it stays in the area.
“I just don’t think I’ll be able to repeat it, so unless it roosts somewhere a bit more accessible, I’ll wait for the next rare bird to appear,” he told PA.
The bearded vulture has been classified by the IUCN Red List of Threatened Species as being near threatened.