The NHS has referred hundreds of its patients and staff to the police under a controversial anti-terrorism programme.

Since July 2015, the Government’s Prevent scheme has required all public bodies to report people they believe to be at risk of radicalisation.

In the year since it was introduced, 420 people were referred to the scheme by the NHS over fears they could be vulnerable to extremism, reported BBC Radio 5 Live.

The Government says Prevent aims to “reduce the threat to the UK from terrorism by stopping people becoming terrorists or supporting terrorism”.

However, 90 per cent of investigations into those reported by the NHS came to nothing, according to information obtained by 5 Live from the National Police Chiefs’ Council.

The Home Office has said more than half a million frontline public sector workers – including at least 150,000 public-facing NHS staff, such as doctors and nurses – have been trained to spot and report potential extremists in their workplaces.

One NHS employee in the West Midlands told the broadcaster she was referred to the scheme when she became more interested in her religion around Ramadan.

Ramadan 2016 - All you need to know

“When I went into work after Ramadan, wearing the scarf, I was getting all this odd behaviour,” she said. “I was asked every single day what my religion was by my colleagues, and I felt I had to explain myself.”

One day she received a letter from HR informing her she had a meeting with a ‘safeguarding lead nurse’, at which a police officer from the counter-terrorism unit was present.

“I thought: what have I done?” she said, adding she was “gobsmacked” when she was told she had been referred under an anti-terrorism programme.

“There was no need for it. I had done nothing wrong, so I knew I had nothing to worry about, but I was really emotional, because I didn’t know what was to come.”

She said she was told the case would not be taken further, but was then visited by the police at her house and has since given in her notice and left the job.

The figures show monthly referrals to the police increased by two thirds from 21 to 35 after the Prevent programme was introduced.

David Anderson QC, head of the government’s terror law watchdog, has called for an overhaul of the Prevent programme and said it was seen as a “spying programme” by many in Muslim communities.

“There is a strong feeling in Muslim communities that I visit, that Prevent is, if not a spying programme, at least a programme that is targeted on them,” he said in October.

Police say arsonist set Florida mosque on fire Show all 9 1 /9 Police say arsonist set Florida mosque on fire Police say arsonist set Florida mosque on fire As Law enforcement officials investigate a fire at the Islamic Center of Fort Pierce part of a burnt wall is seen at the mosque that was attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. Joe Raedle/Getty Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: A Law enforcement official walks near the scene of a fire at the Islamic Center of Fort Pierce which is the mosque that was attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Law enforcement officials investigate a fire at the Islamic Center of Fort Pierce, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Wilfredo Ruiz, from the Council on American-Islamic Relations, (2nd L) speaks to the media with other officials in front of the Islamic Center of Fort Pierce as Law enforcement officials investigate a fire at the center, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Law enforcement officials investigate a fire at the Islamic Center of Fort Pierce, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Hamaad Rahman (C) whose father is an Imam of the Islamic Center of Fort Pierce arrives to speak to the media as Law enforcement officials investigate a fire at the center, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Law enforcement officials investigate a fire at the Islamic Center of Fort Pierce, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Law enforcement officials investigate a fire at the Islamic Center of Fort Pierce, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images Police say arsonist set Florida mosque on fire FORT PIERCE, FL - SEPTEMBER 12: Law enforcement officials investigate a fire at the Islamic Center of Fort Pierce, which was the mosque attended by the Pulse nightclub gunman, who killed 49 people in Orlando on September 12, 2016 in Fort Pierce, Florida. Law enforcement officials are investigating the fire as an arson and say that surveillance cameras show a person approaching the mosque moments before the blaze on Monday morning. (Photo by Joe Raedle/Getty Images) Getty Images

“In some cases, it is even felt it is targeted not just at Islamist terrorism or extremism, but at the practise of Islam. People who pray or who wear the veil, for example, are sometimes felt to be under suspicion.”