Nigeria's anti-corruption agency says it has arrested former Power Minister Saleh Mamman a week after he was sentenced to 75 years in jail on corruption charges.

The Economic and Financial Crimes Commission (EFCC) said Mamman was arrested in the early hours of Tuesday in the northern Kaduna state after "weeks of surveillance and intelligence gathering".

In a statement, the agency said the former minister had gone into hiding after being convicted by a court in the capital Abuja earlier this month.

Mamman was found guilty on 12 counts related to the diversion of funds meant for two hydroelectric power projects.

The court ruled that prosecutors had proved their case beyond reasonable doubt. He was sentenced in absentia after failing to appear in court.

His arrest on Tuesday marks a rare follow-through in the fight against high-level corruption, with convictions of top officials uncommon in the West African nation.

EFCC chairman Ola Olukoyede said authorities were determined to ensure the former minister served his sentence.

"For us, getting the convict to serve his jail terms is extremely important in view of the seriousness with which we are tackling corrupt practices," he said.

The judge who ruled on his case said during the trial that the EFCC had shown that Mamman and his associates diverted at least 22bn naira ($14m; £10m) intended for critical electricity projects.

The judge described the diversion of public funds as a gross abuse of public trust and said proxy companies and associates were used to siphon money from the projects.

The former minister was sentenced for multiple prison terms across the charges, which are to run consecutively, making it to a total of 75 years.

He also faces a separate corruption trial in Abuja over allegations of fraud involving 31bn naira. Earlier this month, another judge issued a warrant for his arrest after he failed to appear in court in that case.

Mamman served as Nigeria's power minister between 2019 and 2021 under former President Muhammadu Buhari.

His conviction has sparked outrage over Nigeria's lingering electricity problems, especially as he had promised to improve power supply while in office.

Despite being one of Africa's biggest energy producers, Nigeria still faces frequent blackouts and power cuts which affect homes and businesses.

Many people rely on fuel generators for electricity, but rising fuel costs have made this increasingly difficult.