Andriy Derkach, a Ukrainian lawmaker who had previously been accused by the United States of being a Russian agent, was a part of a Russian spy network, according to Ukraine’s top internal security agency, which announced the discovery on Friday.

According to the State Security Service (SBU), Derkach, whose whereabouts are unknown, organized a network of private security companies to facilitate and support Russian units’ entry into cities during Moscow’s invasion on February 24.

Derkach could not immediately be reached for comment. He has previously denied wrongdoing and said he has been targeted for exposing corruption.

In a statement, the SBU cited testimony from Derkach’s parliamentary aide Ihor Kolykhayev. It said he was arrested at the beginning of the war, and accused him of being a go-between between Derkach and Russia’s military intelligence agency.

Kolykhayev said Derkach’s security firms “had to ensure the passage of (Russian) vehicles, get into armoured vehicles with Russian flags, and thus ensure (the Russian army’s) peaceful entry into the city.”

The SBU said Derkach received sums of $3-4 million every several months in order to fulfil the plan.

Derkach was sanctioned by the U.S. Treasury in September 2020 for what it said were attempts to influence the 2020 U.S. presidential election.

The Treasury’s sanction announcement at the time said Derkach had been “an active Russian agent for over a decade.”