The Department for the Economy does not monitor cases of workers fired for whistleblowing, it has emerged.
Economy Minister Diane Dodds added her department did not collect information about the number of people dismissed after being unable to attend work because of the pandemic.
She said there was no requirement for businesses to notify her department of such cases or the reason for dismissal.
The Public Interest Disclosure (Northern Ireland) Order 1998 protects people who report wrongdoing in their jobs from dismissal or poor treatment.
Changes to the law, including closing loopholes and matters relating to public interest, came into force in October 2017.
One significant change was the extension of the definition of a ‘worker’ in the health service to include student nurses and midwives on work experience.
The news came to light following a series of Assembly questions tabled by People Before Profit MLA Gerry Carroll, who said dismissal figures needed to be monitored.
"It is extremely concerning that the Economy Minister and her department do not record the number of workers who have been dismissed for whistleblowing or requiring to shield during Covid," he added.
"The minister has indicated that she has no plans to introduce legislation to strengthen workers’ rights, although given the fact that her department is not collecting information, it would appear impossible for them to have an accurate picture of the reality for workers, especially those who raise issues in their workplace.
"The fact that there is no compulsion on employers who dismiss staff to detail the reasons why sends a signal that the minister is ignoring the plight of workers in today’s society.
"We have heard countless stories of some employers using Covid as an excuse to dismiss workers or change their terms and conditions.
"The minister needs to urgently ensure that this information is captured, otherwise she will continue to fail workers across our communities."
Ms Dodds said while her department did not collect this information, "in these challenging times, I would encourage employers to treat all staff fairly and respect employee rights".
Turning to people shielding, she said employers should give consideration to alternative arrangements, such as statutory sick pay and the Coronavirus Job Retention Scheme.
"As I have stated previously, any employee who believes they have been unfairly treated should raise a grievance with their employer," she added.
"In other circumstances related to their treatment or contract of employment, they may be able to complain to an industrial tribunal.
"Anyone who finds themselves in this position may wish to consider contacting the Labour Relations Agency on 03300 555 300 for confidential and impartial information.
"In addition, the Law Centre NI provides free and independent legal advice, subject to capacity, on employment rights."