Ukraine is trying to get ahead of crypto-savvy Russian politicians who might turn to digital currencies in trying to escape growing efforts to financially isolate the Kremlin and its allies.

On Saturday, Ukraine Minister of Digital Transformation Mykhailo Fedorov called for information on crypto wallets held by Russian and Belorussian politicians. “War crimes must be pursued and punished!” he said in a tweet.

Artem Afian, a Ukrainian lawyer gathering addresses, according to Fedorov, told CoinDesk the minister’s goal is to “stop Russian politicians from using crypto and avoiding sanctions.” This would become especially important if Russia is kicked from the SWIFT international banking system, he suggested.

The call-to-action adds another layer to Ukraine’s post-invasion crypto strategy, which includes soliciting donations in bitcoin (BTC) and ether (ETH). Both efforts highlight how cryptocurrencies can jump borders as a tool for those seeking assistance as well as people trying to evade the law.

Read more: People Are Sending Millions in Bitcoin to Aid Ukraine's Military as Russia Advances

Russia-linked wallet addresses will be reported to government sanctions offices, to cryptocurrency exchanges and to Chainalysis, the crypto tracing company, Afian said via Telegram. Doing so could make it more difficult for offending addresses to cash out.

A representative for Chainalysis wouldn’t comment on discussions with the Ukrainian government.

“Chainalysis is monitoring for on-chain indicators of crypto-based sanctions evasion by Russian actors,” the company tweeted late Friday. “We will alert our partners in government of any relevant activity and provide public updates where possible. So far, on-chain tx vols across the region are stable.”

Ruble-crypto trading pairs have seen a nearly ninefold surge in daily volume since the days leading up to the invasion, the company said. It suggested this was the result of Russian citizens “trying to preserve their savings,” and was not necessarily criminal activity.

Ukrainian hryvnia-crypto trading pairs experienced a similar spike in volume, Chainalysis said.