Delhi's Anti Corruption Branch (ACB) has asked the Accountant General of Central Revenue if there were any violations in awarding contract of over 350 tankers by the then Sheila Dikshit-led-Congress government.
The ACB was also probing whether Delhi Chief Minister Arvind Kejriwal was delaying the probe into the 358 stainless steel water tanker contract.
"The ACB has sought opinion from Accountant General Central Revenue and asked if there were any violations," ACB chief Mukesh Kumar Meena said.
When asked if appointment of a consultant to overlook the tendering process then, had caused a loss of Rs 36.5 crore to the exchequer, Meena refused to comment.
According to the official sources, the ACB has found that a consultant had been appointed arbitrarily on nomination basis, causing the loss of Rs 36.5 crore.
Though the tender of a company was earlier rejected on the ground that it was the only application, work was later awarded to another company on the basis of a single tender.
Sources said the work was given at higher rates compared to the rates quoted by another firm at Rs 323.9 crore.
The Rs 400-crore water tanker scam involves alleged favouritism for private water tanker operators supplying water to areas falling outside the Delhi Jal Board's network.
Earlier the ACB had questioned Kejriwal's political adviser Vibhav Patel on May 17 and also summoned suspended AAP leader Kapil Mishra to join the probe.