Russian films are being made available through Apple's iTunes service without the consent of the copyright holders, the BBC has learned.
The popular films, dating from the Soviet era, are being made available to download as smartphone apps.
But the original film-makers have not given their permission for the films to go on sale.
Apple said it took copyright complaints seriously and took action as soon as it received a complaint.
Films available via iTunes include old favourites such as Gentlemen of Fortune, Assa, The Diamond Arm, Kin-dza-dza and Cheburashka.
Despite their age, the films and cartoons are still protected by copyright.
The owners of the copyright on the films - Russian film studio Mosfilm and the Joint State Film Collection (Obyedinennaya Gosudarstvennaya Kinocollectsia) - have told the BBC they have not given consent for their films to be sold in the app stores.
"It is illegal to present our films as applications either in iTunes or on any other internet site. It is permitted only on our own Mosfilm site," Svetlana Pyleva, Mosfilm's deputy director general, said in an interview with bbcrussian.com.
"The only official internet site where you can watch legal Mosfilm content is the Mosfilm site," she said. "There are no third parties which we have permitted to use our content."
Ms Pyleva said Mosfilm management was aware of the problem and was preparing to submit a claim to Apple.
"Maybe Apple will take appropriate measures and help us solve the problem," she said.
Apps, self-contained programs or content for gadgets, are often written by programmers working independently or under contract for a company keen to get their creations in front of a wider audience. Apps can be original or adaptations of existing programs and games.
Before apps make it to the iTunes store, they are submitted to Apple for consideration and, if approved, are made available on iTunes.
Ekaterina Toropova, press secretary of the Joint State Film Collection, which holds copyright for some of the films put on the Apple store, told bbcrussian.com that it had not issued licences for such applications.
"The [Joint State Film Collection] retains all exclusive rights," said Ms Toropova.
Until told by bbcrussian.com, the JSFC was unaware that some of its films, including Cheburashka, were being sold as an app for iPhones and iPads.
"We'll try to get in touch with the developers," said Ms Toropova. "It is possible that they obtained licences from someone else and they themselves are in the dark as they are sure that they sell a legitimate product."
"We'll explain to them that they are wrong," said Ms Toropova.
In response, Apple said it would investigate.
"We understand the importance of protecting intellectual property and when we receive complaints we respond promptly and appropriately," Christine Monaghan, Apple's official representative, told bbcrussian.com.
The BBC's Russian Service spoke to Vladimir Penshin - a programmer who lives in Ukraine who has created an app for iTunes from the film Cheburashka.
"Of course, I do not have any licence agreement," he said. "This is all very simple. The companies, who can have complaints, submit them to Apple and Apple notifies me that they have to withdraw the application."
Mr Penshin confirmed to bbcrussian.com that he deliberately decided to offer unlicensed material for sale to gain profit.
Mr Penshin has also created and offered for sale an application based around the animated series Penguins of Madagascar, produced by US studio Dreamworks.
"I realise that this is wrong," he said. "Maybe I am breaking the law."