The Ceylon Petroleum Corporation (CPC) says a special inspection is being carried out on a consignment of petrol imported by Lanka IOC to the Trincomalee Harbour.
Measures have been taken to conduct test on petrol samples, CPC Managing Director Susantha Silva said.
16,000 metric tonnes of petrol brought down by Lanka IOC had reached China Bay last evening while it has been reported that the quality of the fuel has sparked controversy.
Mr Silva said the unloading of the fuel shipment has been prohibited without special tests.
The CPC added that substandard fuel will not be allowed to be brought into the country.
Meanwhile industry trade unions claim that initial laboratory tests have confirmed that the petrol is substandard.
However, attempts by Ada Derana to contact an official of the Lanka Indian Oil Company (LIOC) failed.
Last month 5,000 metric tonnes of substandard diesel imported by Lanka IOC was rejected by Ceylon Petroleum Storage Terminals Limited (CPSTL).
