A British 17-year-old's exposé of an alleged Russian-backed crypto laundering network has made its way all the way to the Kremlin, landing him on a fresh list of sanctioned individuals.

Alexander Browder was sanctioned by Russia's Foreign Ministry on Wednesday over what it called "defamatory speculations and false information".

The teenager, along with four other British nationals, will now be banned from entering Russia.

Browder's report, titled "Confronting the Illicit-Finance Hydra in Crypto Markets: Protecting Retail Investors and Disrupting Hostile Government Exploitation," was published by the Henry Jackson Society think tank in March.

In it, Browder lifted the lid on alleged illicit crypto laundering operations, writing that around $350 billion had been laundered by various states including Russia, Iran and North Korea.