The left back appeared 40 times in all competitions and scored three goals for Dragões last season.
The 25-year-old, who has been capped ten times by Nigeria, sealed FC Porto’s 30th Liga Portugal Bwin title after netting a stoppage time winner against bitter rivals Benfica in May.
The Daily Star has reported that Sanusi, who is represented by super-agent Jorge Mendes is under contract at the Estádio do Dragão until 2025.
But the Portuguese champions would be willing to sell the Nigerian and have set an asking price of at least £20m.
The Seagulls have also been heavily linked with Paraguayan wonderkid Julio Enciso. Albion attempted to sign the 18-year-old from Paraguayan Primera División side Club Libertad in January but talks broke down.