The PSNI has used anti-terror spying laws to investigate potential breaches of Covid regulations, it has been claimed.
A leading privacy campaign group said its use here to probe such breaches is "entirely disproportionate".
Introduced in 2000, the Regulation of Investigatory Powers Act (RIPA) - commonly known as the 'snoopers' charter' - was put on the statute books to help authorities fight terrorism and organised crime.
It gives various government authorities the power to intercept phone calls, text messages, emails and internet communications.
Over the years it has been updated on several occasions to increase its scope and cover more forms of communication, most recently in emergency legislation brought in at the outbreak of the coronavirus pandemic in March last year.
A well-placed source told the Belfast Telegraph that the PSNI has used the controversial powers to investigate potential breaches of Covid regulations in Northern Ireland.
Asked about this, a PSNI spokesperson said: "We can neither confirm nor deny and no inference should be drawn from this."
Asked via a Freedom of Information request to detail the number of times RIPA has been used in relation to the pandemic, the PSNI refused to answer, stating that the estimated cost of complying with the request would exceed the "appropriate costs limit" set by the act.
Silkie Carlow, director of the campaign group Big Brother Watch, said the PSNI must reveal how it has used RIPA to investigate Covid breaches.
"The use of such invasive search powers, like looking at someone's phone data, to investigate breaches of health regulations is completely disproportionate," she said.
Lana Adamou, a lawyer with the human rights group Liberty, said "we all want to get through the pandemic as soon as possible", but "the Government's focus on criminal justice and punishment has created the perfect environment for our rights to be undermined".
"Liberty has always supported reasonable and proportionate measures to combat Covid but intrusive tools do not serve public health, they instead pave the way for the normalisation of surveillance and state snooping of all of us.
"Those in power are still pursuing the failed strategy of trying to police us out of this pandemic.
"But strategies based on punishment and division don't work, and instead we should be bridging divides with policies that protect everyone.
"Supporting people, and helping people follow guidance, is the best way to keep everyone safe."
SDLP MLA Dolores Kelly, a member of the Policing Board, said human rights issues must be taken into account when the PSNI use RIPA powers.
"The use of RIPA powers is often controversial and should be subject to the highest standards of transparency and accountability," she said.
"In the current environment, the police clearly need to use the tools available to them to prevent transmission of the virus and to safeguard public health.
"But that must be done in line with the strict human rights framework governing the use of these powers."
People Before Profit MLA Gerry Carroll said we need a public health response to the pandemic, not a "secretive, repressive state response".
"This act, as I understand, permits the use of wiretapping, bugging of houses and vehicles and the use of informers," the West Belfast MLA said.
"Have these mechanisms been used here and if so, how many times?
"The public needs transparency on these matters.
"We cannot have an approach which allows for increased surveillance and police powers."
Under RIPA, a warrant must be signed by the relevant secretary of state, or in Northern Ireland the Lord Chief Justice, and then approved by a judicial commissioner.
Under the new emergency coronavirus legislation, however, the investigatory powers commissioner is allowed to directly appoint temporary judicial commissioners for terms of up to six months.
"Unless there are enough available judicial commissioners, there is a real danger that the warranty regime would cease to function, which would have extremely significant impacts on national security," reads the Coronavirus Act 2020's summary of impacts document.
RIPA legislation also allows for "direct surveillance" - the use of undercover investigators to follow and directly monitor individuals.
Also covered within the act is "intrusive surveillance", that is, placing covert listening devices and filming equipment in private locations.