The Central Bank is due to be called before the Oireachtas Finance Committee in relation to insurance companies charging existing customers more than new customers.
Sinn Féin finance spokesman Pearse Doherty said the committee has agreed to investigate the practice of dual pricing, where insurance companies are "discriminating existing customers by giving inflated renewal prices".
Mr Doherty said the committee will be writing to the Central Bank, Competition and Consumer Protection Commission (CCPC), the Consumers' Association of Ireland and Insurance Ireland to request they appear before it.
The Donegal TD said: "there may be others we want to bring in", adding the committee is planning to hold hearings "as soon as possible".
Mr Doherty has written to the Central Bank and CCPC, asking them to investigate the issue.
“It is clear the issue of price discrimination in the insurance market is widespread, systematic, unjustifiable and in breach of the Consumer Protection Act,” he told the governor of the Central Bank. “However, no formal study or investigation into this issue has taken place.”
Speaking in the Dáil on Thursday, Mr Doherty said: “This practice [dual pricing] is widespread across the industry and wholly unjustifiable.
“It is a systematic scam, costing costumers hundreds of euros every year without them even knowing it is happening.
“These companies exploit customers who do not know about dual pricing, relying on their loyalty to charge extortionate prices and push up their own profit margins . . . It’s a rip-off on a vast scale, but nothing has been done to stop it by this Government.”
Replying for the Government, Minister for Communications Richard Bruton said Minister for Business Heather Humphreys had already asked the CCPC to study the activities of the insurance industry, including brokers.
“There is no doubt that some of the practices there are not satisfactory. Greater transparency and scrutiny is being demanded of their practices which the commission will undertake.”
Mr Bruton said the Government is not content with what was being done already and there is a review to see if there are further measures that could be taken to make this more effective.
He pointed out some insurers had withdrawn from the market and the Government had to maintain the presence of diverse players in the market.