Snapchat's parent company says the US messaging app has been registered with Russia's technology regulator without its knowledge.
Snap told the BBC that the Roskomnadzor agency had unilaterally put it on its register of information distributors.
The move means Snapchat will be required to keep all messages for six months and make them accessible to the Russian security services.
Snap said it had no intention of complying with the rule.
A spokesman for the company said it had provided "very basic contact information" to Roskomnadzor, but "not for the purpose of registering us".
Snap is the first Western social media company to find itself on the list. Whatsapp and Facebook Messenger have not been added.
Russia's new data laws require "information distribution organisers" to register with the regulator and store users' data for six months. The requirements come into force next year.
Companies must also hand over their encryption keys when asked, in line with Russian anti-terror legislation.
Non-compliance comes with a risk. Chinese messaging service WeChat was blocked earlier this year, Russian website VC.Ru reported [in Russian].
Snap does not have a specific figure for Russian users, but says there are 57 million daily users in Europe as a whole.