Non-national workers with legal work permits are being treated as slave labour in this State, the Consumers Association of Ireland (CAI) claimed last night.
The watchdog organisation has received "a mountain of complaints', particularly from the fast-food and hotel sector, of the exploitation of out-of-state workers.
Unscrupulous bosses, it has been told, are not paying proper wages and are threatening to have visas revoked if workers complain to the authorities.
The chairman of the Consumers' Association, Mr Michael Kilcoyne, has called on the Tanaiste and Minister for Enterprise, Trade and Employment, Ms Harney, to appoint an official to investigate the claims.
However, IBEC last night said the claims were "grossly exaggerated" and it would not support any employer found flouting the law.
Its enterprise spokesman, Mr Brendan Butler, said many fast-food companies had been using foreign workers for over a decade.
"They are used to operating within best international practice," he said.
There was no point in employers treating foreign workers badly because they needed them, and the whole economy would suffer if Ireland got a bad reputation internationally for exploitation.
Mr Kilcoyne said: "We have received a mountain of complaints that rogue employers are not paying proper wages to these workers.
"In some cases foreign workers have been told their visas will be revoked if they complain of the treatment they are receiving.
"These threats are being made by unprincipled employers, particularly in fast-food chains and the hotel sector.
"There are a number of recruitment agencies bringing these workers in and agencies in foreign countries are also recruiting workers to come here.
"They are legally here and with the necessary visas so that they can work. But they should not be treated in this way," Mr Kilcoyne said.
As the visas were issued by the Tanaiste's Department there should be a policing system to ensure these workers were not exploited.
"These visitors are being treated as slave labour. They are not being properly paid and are being exploited by rogue employers," he added.
A spokeswoman at the Department Enterprise, Trade and Employment said any such complaints would be investigated.
She said: "Protection of Irish labour law applies to immigrant workers in exactly the same manner as it would to native Irish workers.
"The Labour Inspectorate of this Department has an ongoing responsibility for monitoring the employment conditions of various categories of workers, including immigrant workers.
"If anybody is aware of instances of apparent abuse of foreign workers these should be brought to the attention of the Inspectorate of the Department.
"These complaints will be investigated, and where there is evidence that immigrant workers are being denied any entitlements under the Employee Protection Act, such action, even including prosecution as is necessary, will be taken to ensure that the employers concerned end up complying with the law," she said.