Anti-corruption officials in Nigeria said Tuesday that fraudster Hope Olusegun Aroke masterminded a $1 million internet heist while inside the Kirikiri Maximum Security Prison in the capital of Nairobi.

Aroke is currently serving 24 years in the prison after being convicted of fraud in 2015. Nigeria's economic and financial crime commission said that Aroke continued his fraudulent activity while in the prison, using a "network of accomplices" that targeted victims around the world.

“Preliminary investigation revealed that the convict, against established standard practice, had access to Internet and mobile phone in the Correctional Centre where he is supposed to be serving his jail term,” the commission said.

The commission was also puzzled at how Aroke managed to go to the hospital during his jail term, where he was able to then meet with his family and attend social events.

When Aroke was first arrested in 2012 for fraud, he was based in Malaysia, where he claimed to be a student at the Kuala Lumpur Metropolitan Univerisity College. In reality, he was behind an international internet fraud scheme.

Online fraud is a major issue in Nigeria. In September, it was reported that 167 people in Nigeria had been arrested in a four-month global operation targeting a multi-billion dollar internet scam.

Types of schemes include Business Email Compromise, where the Nigerian scammer impersonates executives or business contacts and attempts to convince a business to wire money to the criminal's account.

Romance scams are also common, where the scammer will target a western woman online, and ask for money or gifts as part of a fraudulent relationship. The Federal Trade Commission said that in 2018 there were more than 23,000 Americans targeted by online romance scams.