"We cannot consider the test results objective, knowing the originally prejudiced attitude by a senior environmental official against Ochakovo," Yury Lobanov, vice president and chief engineer of the company, said in an apparent reference to Oleg Mitvol, deputy chief of the environmental regulator.
Lobanov added the brewery, whose operations had previously been suspended for five days over the alleged violations, had not received official notification of the test results.
The Russian Ministry of Natural Resources and its watchdog accused Ochakovo of spilling unfiltered industrial sewage, possibly containing malt into the offshoots of the Moskva River in the west of the city in early July.
Mitvol, who is known for his high-profile environmental investigations, said "the water samples confirm that it was the Ochakovo brewery that contaminated the Moskva offshoots."
But the company said information from the Federal Service for the Oversight of Natural Resources often lacked hard facts to back their allegations. "We are waiting for the results of water tests by the certified state laboratory," Lobanov said. The company expects the first results later Tuesday.
The company said checks of the storm water and industrial drain systems had found no violations.
The company said the brewery was continuing to work as usual.
Mitvol said earlier the watchdog could raise the issue of seizing the brewery's property if the tests confirm the enterprise is responsible for the contamination.