Nigeria's anti-graft agency said it had arrested 792 suspects in a raid on a building believed to be a hub for fraudsters who lured victims with offers of romance, then pressed them to hand over cash for phoney cryptocurrency investments.

The suspects, including 148 Chinese and 40 Filipino nationals, were detained on Dec. 10 at the seven-storey Big Leaf Building in Lagos, Nigeria's commercial capital, Economic and Financial Crimes Commission spokesperson Wilson Uwujaren said.

The luxury building housed a call centre mostly targeting victims from the Americas and Europe, he added.

Staff there would make contact with people through social media and messaging platforms, including WhatsApp and Instagram, them seduce them online or offer them apparently lucrative investment opportunities, Uwujaren told reporters.

Once victims were hooked, they were pressured to transfer money for fake cryptocurrency schemes and other non-existent projects.

"Nigerian accomplices were recruited by the foreign kingpins to prospect for victims online through phishing, targeting mostly Americans, Canadians, Mexicans and several others from European countries," Uwujaren said.

"Once the Nigerians are able to win the confidence of would-be victims, the foreigners would take over the actual task of defrauding the victims," he said.

Uwujaren said the Commission was collaborating with international partners and would look into potential links to organised crime. Its agents seized computers, phones and vehicles in the raid, he added.