CPC sources say the scam is going on by using two letters obtained from the buyers, Bitumen Lanka and Oru Mix.
In its letter, Bitumen mentions it will buy 40,000 barrels of tar, and from 02 September, 2015, it has been issued with tar at Rs. 46.20 per kilo.
Oru Mix promises in writing to buy 20,000 barrels, and the CPC issues same at Rs. 48.50 per kilo.
However, other buyers have to pay Rs. 53 per kilo, and they have to buy not from the CPC, but from Bitumen Lanka and Oru Mix which use facilities at the CPC Muthurajawela complex for the purpose.
The CPC top management is allowing a free hand to the two companies, while intentionally delaying the issuance of tar to other buyers.
It has supplied to Bitumen Lanka and Oru Mix, while postponing an order by CECB that has undertaken a Rs. six billion project to develop 28 roads in Polonnaruwa.
However, when payments are made, just like the others, these two companies are allowed to pay on a weekly basis.
An assistant manager T.G. Jayasinghe, who had questioned these irregularities, had been transferred to Kurunegala by the corrupt top management of the CPC.
Loss in importation too
Furthermore, it has also caused a loss of nearly Rs. 400 million to the institution in the importation of tar.
That is by making payments to a supplier at the 2014 rates in 2015 when world market prices declined, although it had failed to deliver an order on time.
When contacted, a top CPC official said he was not responsible for any financial irregularity and that he was unaware of any such occurrence either.
CPC sources add that the corrupt practices of the top management have allowed Lanka IOC to claim a 70 per cent stake in the local tar market.