Russian news agencies say authorities have filed criminal charges against the owners of four companies in the Pacific region of Primorye for holding dozens of captive whales in shoddy and cramped conditions.
The case had sparked outrage in Russia and criticism from President Vladimir Putin when images of the captive whales, which included orcas and belugas, were published last year.
Russian media have called the conditions a "whale prison."
The RIA-Novosti and TASS news agencies said February 28 that the Federal Security Service had accused the owners of violating federal fishing laws, and ordered the animals released.
"An examination showed that the animals were kept in unsatisfactory conditions, and must be released into their natural habitat," TASS quoted the service as saying.
The whales were destined for sale in aquariums abroad.
Kremlin spokesman Dmitry Peskov said last week that Putin had personally gotten involved in the issue. Peskov also noted that Russia allows catching whales for scientific purposes.
The issue had drawn international attention as well, with a online petition to release the whales, circulating on social media.
Actor Leonardo DiCaprio was among celebrities who had shared the petition, which has gathered more than 900,000 signatures.