The Competition and Consumer Protection Commission (CCPC) confirmed it is carrying out ongoing compliance activities in relation to pricing displays for fuel retailers.
It received 83 complaints over the past week, as drivers saw record-high prices at the pumps.
The CCPC has written to petrol stations to remind them of their obligations under consumer protection law, and also to a trade association warning them about making public statements around future increases in fuel prices.
Speaking in the Dáil on Wednesday, ahead of an emergency vote to cut excise duties, Labour TD Ged Nash said "there's a special place in hell for petrol pump operators who hiked prices" ahead of the planned tax cuts.
Michael Grubb, Professor of Energy and Climate Change at University College London, said oil producers are making huge profits from the current fuel market.
Mr Grubb said: "Having set their quotas, if the Russians pulled out of that system in terms of supply, we've seen what happens to the oil price. If you can sell all that you've agreed to produce at $137 a barrel or more, why would you agree to pump more so that the price can go down. So one of the features of the current crisis is those selling fossil fuels are making an absolute killing at present."
