A Russian company that runs a so-called "whale jail" in the east of the country has been fined 28.1 million rubles ($433,000; £430,000).
White Whale is one of four firms holding killer and beluga whales in small enclosures on the Sea of Japan, which they say is legal.
But a Vladivostok court on Friday ruled the company broke fishing rules.
Cases against the other three companies are expected before the courts in the next week.
Although Russia allows the capture of whales for scientific purposes, the fear is these animals are bound for theme parks or aquariums in China.
The confined whales have scandalised scientists, politicians and activists at home and abroad.
Environmental groups have demanded the release of the mammals ever since news of the "whale jails" first broke.
About 10 orcas and 90 beluga whales are currently being held at the facility.
The Russian government however seems to be bowing to pressure to end the practice. In February, President Vladimir Putin asked his government to look into the whale enclosures.
Authorities have since said the whales will be released, but it is not clear when.
Environment minister Dmitry Kobylkin this week said they would be freed in July or August, but officials had previously said this would happen in May or June.