The anti-Iran group whose founders include current and former administration officials has sent a letter to IMF Managing-Director Christine Lagarde criticizing the IMF's relationship with Iran.
In reply, the IMF said on Tuesday that its relationship with the Central Bank of Iran is based on its constitution, noting that Iran's membership does not contravene US or EU sanctions on Tehran.
"According to our constitution... the IMF's holdings of each member's currency are maintained with the central bank of the relevant member, including Iran. There is nothing in the EU or US sanctions regimes that is inconsistent with these arrangements," IMF spokesman William Murray said.
Earlier in April, Lagarde praised Iranian President Mahmoud Ahmadinejad's subsidy-cuts plan, and described it as a brave move which should be followed by other countries.
Lagarde made the remarks, addressing a joint meeting of the World Bank and the IMF.
She referred to Iran's measures in reforming its subsidiary system in the past two years as exceptional, and called on other world countries to follow the role model of Iran in carrying out reforms.