On Wednesday, Russia formally and publicly accused Turkey’s president, Tayyip Erdogan, of being in collusion with the Islamic State and profiting from their illegal oil trade. The Islamic State has seized oil wells and fields in territory that they have captured and have been selling the oil on the open market to keep funding their operations.

The Russian deputy minister for defense declared that Turkey was the main destination for oil that Russia considers to be stolen from its rightful and proper owners, according to NBC News. Russia went on to say that Turkey resells the stolen Islamic State oil and the profit has gone directly into the personal pockets of President Erdogan and his family.

Russia has shown surveillance satellite photos of Islamic State controlled oil fields and installations in both Iraq and Syria. The Russians have photos of oil tanker trucks being loaded up and driven across the border into Turkey. Erdogan has been accused in the past and has denied all involvement with the Islamic State oil trade. The Russians have not presented any proof to substantiate their allegations against Erdogan and his family.

The Russians have tried to imply Erdogan involvement by pointing to his son being the energy minister and chief of the largest energy conglomerate in the country. Thus far, the Russians have only been hurling accusations and inflammatory rhetoric but they are asking the Turkish people to find out the truth for themselves and remove Erdogan from power.

The oil revenue is what keeps the Islamic State going. It uses the money to purchase arms and supplies as well as to pay its soldiers and to provide monthly stipends for the soldier’s families. Estimates are that the Islamic State can bring in between $8-$10 million every month from its oil smuggling operations.

Turkey is part of the American led coalition battling the Islamic State in the Syrian civil war. The Russians are siding with Bashir Assad who wishes to hold onto his presidential power in Syria.