Nigerian President Muhammadu Buhari is pressing forward with his crackdown on corruption and is sending a clear message that corruption no longer will be “business as usual” in his country. During his September 28th speech before the U.N. General Assembly, President Buhari urged the international community to step up its efforts to locate and return to Nigeria millions of dollars of funds that allegedly were stolen during previous administrations and are being held in foreign bank accounts. Buhari alleges that former government officials stole around $150 billion from government coffers and repatriated those funds to foreign bank accounts. Elected in May on a pledge to address corruption, Buhari has vowed to recover the stolen money and to hold accountable those responsible.

The President appears to be delivering on his promise. According to an official at Nigeria’s Economic and Financial Crimes Commission, earlier this week, Nigeria arrested the co-chairman of local oil firm Atlantic Energy on corruption and money laundering charges. The arrest appears to be part of a widening graft investigation that also has swept up former Nigerian oil minister Diezani Alison-Madueke, who was arrested last week in London. In 2014, the governor of Nigeria’s central bank accused Ms. Alison-Madueke of misappropriating billions of dollars in oil receipts from the state-owned oil company and handing out contracts to Atlantic – an allegation that Ms. Alison-Madueke has denied.

It is unclear whether additional arrests are planned, but this could be the beginning of a broader anti-corruption dragnet.