Alexey Pertsev, a developer of Tornado Cash could have links with the Russian FSB

Alexey Pertsev worked for a Russian security firm.

Alexey Pertsev likely worked for a Russian security firm linked to state intelligence agencies before contributing to Tornado Cash.

According to the Kharon intelligence firm, Pertsev worked for Russia-based Digital Security OOO in 2017. The U.S. Treasury sanctioned the company in 2018, alleging that it had supported Russia’s Federal Security Service (FSB) since 2015.

Pertsev was not among the five entities and three individuals named by Treasury in its 2018 report. Instead, Kharon says he discovered Pertsev’s name in an archive on the Digital Security OOO website.

While Digital Security OOO may not have worked solely for the FSB, Pertsev’s involvement with the company appears to be quite significant. In a statement to Fortune from Nick Grothaus, vice president of research at Kharon, said that Pertsev “was working for Digital Security OOO before the U.S. Treasury sanctioned the company for assisting the FSB.“

Kharon also noted that the Tornado Cash code was partially developed by PepperSec, a Delaware-based company of which Pertsev was the founder and CEO. However, he did not establish a direct link between PepperSec and Digital Security OOO, nor did he establish a link between PepperSec and Russian intelligence agencies.

Pertsev’s wife, Ksenia Malik, denied that Pertsev had any ties to Russian intelligence agencies. She told Coindesk that Pertsev did not “ever been associated with the FSB in Russia or similar organizations“. She did not comment on Pertsev’s alleged involvement in Digital Security OOO.

Malik added that she and her husband initially “moved to the Netherlands in the hope of a quiet, stable and free life, which is unimaginable in military Russia“.

Tornado Cash was sanctioned by the U.S. Treasury’s Office of Foreign Assets Control on August 8. Alexey Pertsev was arrested by Dutch authorities a few days later.