Nigeria's President Bola Ahmed Tinubu on Friday suspended a major national welfare programme designed to help ease poverty, a spokesman said, amid a spiralling corruption scandal.

The National Social Investment Programme Agency (NSIPA) has provided cash transfers for some of the country's poorest people as well as funds to help the young and offer school meals.

The president had "suspended all administered programmes by the National Social Investment Programme Agency... further to the ongoing investigation of alleged malfeasance in the management of the agency and its programmes," the spokesman said.

"During the period of this suspension, all NSIPA-related activities, including but not limited to all distributions, events, payments, collaborations and registrations are now frozen."

The suspension would initially last six weeks, he said.

On Monday Tinubu suspended his poverty minister following allegations she diverted public funds into a private bank account.

The opposition Peoples Democratic Party (PDP) had called for Betta Edu to be sacked and prosecuted "over the alleged looting of N44 billion", almost $50 million, from a social investment fund "meant for the well-being of the poor".

It claimed this included "N585.2 million audaciously diverted by her to a private account".

The measure against the humanitarian affairs and poverty alleviation minister came days after another senior official was suspended over corruption allegations.

Halima Shehu, the head of NSIPA -- which falls under the poverty ministry -- was arrested and released on bail, while former poverty minister Sadiya Umar-Farouq was also taken for questioning, according to local media.

Tinubu came to power last year promising to crack down on graft in Nigeria.

He vowed reforms and swiftly suspended several officials, including former central bank chief Godwin Emefiele and ex-head of the Economic and Financial Crimes Commission (EFCC) Abdulrasheed Bawa.

But Edu is the first minister the president has suspended.

Nigeria remains one of the lowest ranked on Transparency International's widely watched corruption perceptions index.

Africa's most populous nation has seen the poverty rate increase from 40 percent of the population in 2018 to 46 percent in 2023, affecting around 104 million people, the World Bank said last month.