Some etals looked to see if foreign aid disbursements were correlated with onchain bitcoin activity.

We develop a disbursement-timed forensic measure of cryptocurrency activity, combining on-chain Bitcoin transactions and wallet creation, off-chain exchange records, and IP-linked web traffic, and apply it to World Bank aid disbursements covering $238 billion across the 93 recipient countries in our estimation sample during 2018-2024.

They find it is correlated.

Exploiting the administrative timing of aid tranche arrivals, we find sharp, short-lived surges of crypto activity at the disbursement month, driven mainly by anonymous and newly created wallets on both tax-haven and mainstream exchanges.

They conclude bitcoin is being used to launder the aid money.

Blockchain forensics reveal patterns consistent with the placement, layering, and integration sequence of conventional money laundering. We estimate an implied leakage of 2 to 6 cents per aid dollar, which amounts to roughly 1.7 to 4.4 billion dollars of aid diversion across the tranche arrivals we study.

Their evidence of laundering is weak though and is largely based on what they label as anonymity seeking behavior - sending bitcoin anywhere but an exchange, to new addresses, exchange activity increasing, and "mixer" activity increasing.

Who, then, operates this channel? We are explicit about the limits of our evidence. We cannot trace a particular aid dollar onto the blockchain, identify the owner of an anonymous wallet, or fully rule out all legitimate economic responses to the arrival of aid.