Immigration authorities say they are actively pursuing complaints that a private Dublin college owes tens of thousands of euro to students in several developing countries.
On Thursday, RTÉ News revealed that students in India, Pakistan, Nepal, the Philippines and Vietnam had been trying to get fees refunded from Shelbourne College since last May, but to no avail.
The Department of Justice has said it is pursuing the allegations with the owners of Shelbourne College.
The department requires prospective students from a range of non-EU countries to pay fees to one of a number of State-approved colleges before they can apply for a visa to come to Ireland.
If their visa application is rejected, they are entitled to a refund.
The Irish Naturalisation and Immigration Service said the money should be returned within 60 days.
However, up to 50 students abroad are owed fees of more than €4,000 each, some since May.
Shelbourne College has blamed financial management problems and said it will refund the money.
Immigration authorities said they are pursuing the allegations.
They said there can be no doubt that until a visa is granted the money belongs to the student and not the college.