The Venezuelan government has reportedly been taking advantage of tax revenue from an airport near its capital and cryptocurrencies to evade economic sanctions.

According to an investigation conducted by Spanish newspaper ABC, first reported on by CoinDesk, Venezuelan leader Nicolás Maduro and his administration have reportedly been using a cryptocurrency wallet app to turn tax revenue into bitcoin and other cryptocurrencies, which is then sold on exchanges in Hungary, China, Russia, and Hong Kong.

Once the cryptocurrencies are sold on these exchanges, the funds are reportedly sent back to Venezuela. The scheme is helping the country bypass sanctions that have been stopping it from obtaining foreign currency and from participating in the open international market.

Per ABC, tax revenue from the Maiquetia International Airport (IAIM) is collected through an automated system that uses an app called Jetman Pay to turn it into cryptocurrency. The airport is one of the busiest in Venezuela, as it’s located near its capital, Caracas.

Per the publications, once a plane lands on the airport it transfers fiat currencies to purchase fuel. Venezuela’s state-owned oil and natural gas company, Petróleos de Venezuela, uses the app to pay the government taxes.

The system has reportedly been in use since February of last year. A contract that’s allegedly yet to be signed could see Venezuela expand the use of the app to defy sanctions using other airports in the country.

Some believe Venezuela’s oil-backed cryptocurrency, which was sold through an initial coin offering (ICO) to investors, was also a way for Maduro to bypass international sanctions and gain access to foreign currency. Those participating in the token’s sale were notably not able to pay for petros using the Venezuelan bolivar.