Harsha de Silva, representing the main opposition United National Party said the EPF had bought stock in companies that even did not qualify to be listed on Colombo Stock Exchange's main board.
The six second board stocks alone had made 2.7 billion rupee loss of 22.5 percent so far, he said.
De Silva said the EPF had lost 12.2 billion rupees on some of its investments. The biggest losers included 1.8 billion rupees from Laugfs, 740 million rupees from Vallibel One, 87 million rupees from Lighthouse Hotels.
Other large losses came from LOLC (1.0 billion rupees), Browns (945 million rupees), Ceylon Grain Elevators (713 million rupees) and Galadari Hotels (470 million rupees).
Though all stocks had come down from all time highs in late 2011, some investments including Galadari, Lighthouse and Laugfs were controversial from the beginning and earned the fund the doubtful accolade of being the 'buyer of last resort' in the market.
The rating agency Standard & Poor's also assessed the risk for banks in Sri Lanka to be very high partly due to possible conflicts in regulation due to the banking regulator buying stocks in entities over which it had oversight.
The Central Bank insisted that there were firewalls separating the two divisions.
De Silva said in a statement that the opposition will push for "an independent investigation in to the transactions of the entire EPF stock portfolio and thereafter for legal action in the event persons are found to have committed securities fraud."
"In the meantime we will assert that officials of the EPF Department of the Central Bank be summoned urgently to the Public Accounts Committee of Parliament to answer queries on alleged improper transactions at the CSE over the last two years and general queries for the last six years," De Silva said.
De Silva had earlier told reporters that Sri Lanka's central bank governor and the superintendent of the EPF had 'accused and abused' a legislator for questioning investments, raising question of parliamentary privilege.
Sri Lanka however does not have an independent public service to ensure rule of law or justice to the people after a constitution in 1978 destroyed the remnants of the institution of 'permanent secretaries', which was already broken in a 1972 constitution.
Attempt to give some freedom to the people through a mechanism 'constitutional councils" were also scuttled through a recent constitutional change.
Some observers had called for independent management of the EPF before it started investing in stock because it was known to be engaging in financial repression in Treasuries markets.
The EPF's objective of getting the highest interest was at odds with the objective of the public debt department of the central bank which raised money for the Treasury.
In view of this conflict and the general recognition that the EPF beneficiaries were the loser in the conflict, the fund has been labeled a 'captive source' of the state by market participants.
Financial repression (artificially held down rates) generates conditions for asset price bubbles, credit booms, and subsequent high inflation and currency depreciation, resulting in poverty and economic collapses.