U.S. Citizenship and Immigration Services assisted in investigating Emmanuel Oluwatosin Kazeem, a Nigerian national now facing a civil denaturalization complaint filed by the Department of Justice. Kazeem was previously convicted in 2017 on 19 counts—including mail and wire fraud, aggravated identity theft, and conspiracy—for orchestrating a massive identity theft and tax fraud scheme. He was sentenced to 15 years in prison but had his sentence commuted in 2024 after serving about six years. The government now alleges that he concealed his criminal conduct both before and after becoming a U.S. citizen, making his naturalization unlawful. The complaint also claims he entered into a sham marriage to obtain lawful permanent residency and later remarried, further undermining his eligibility for citizenship. Evidence from the investigation showed that Kazeem led a sophisticated operation involving the theft and use of personal identifying information from over 259,000 victims. He purchased tens of thousands of identities from a hacker, distributed them to co-conspirators, and directed the filing of more than 10,000 fraudulent tax returns seeking over $91 million in refunds, with more than $11.6 million successfully obtained. The scheme involved bypassing IRS security measures, using prepaid debit cards to collect refunds, and transferring millions of dollars—including significant sums sent to Nigeria. Federal agents uncovered substantial physical and digital evidence across multiple states, ultimately identifying Kazeem as the mastermind behind one of the largest tax fraud schemes of its kind.