Chinese and Russian authorities are investigating whether container shipping lines engaged in the trade between the two giants colluded over freight rate prices, according to deputy chief of the Russian Federal Anti-monopoly Service, Alexander Kinyov.

The results of the probe into unidentified carriers will be released in mid-August, Mr Kinyov said. The Russian government suspects that the cartel is behind the increase in the price of imports moved by sea, while some analysts grumble it's more of a push to lift Russian carriers by battering their foreign rivals, reported Newark's Journal of Commerce.

"This is a global market and the main route of the container cargo traffic from southeast Asia and China to Europe passes through St Petersburg," Mr Kinyov said.

"We suspect several transport companies of coordinating freight rate increases for container cargo transport on this route," he said.

This is the second large-scale investigation of container shipping by FAS. In 2013, FAS investigated 13 shipping companies, including MSC, "K" Line Russia, HMM, Evergreen, Cosco Russia and Zim Russia, and China Shipping Agency Russia for suspected price-fixing.

FAS has also investigated the carriers for market sharing on a territorial basis. Authorities didn't say why the investigation was suspended in mid-2014.