Maduka Okoye's baby mama just went scorched earth on the Nigerian soccer star in a brutal Instagram rant.

Dutch model Jelicia Westhoff made explosive allegations about the goalie ... accusing him of abuse -- and neglecting their young child because he's too busy getting laid with women and men!

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Westhoff went off on Maduka around the time he was snapped hanging with Cardi B in Italy ... they were also seen hanging out during Paris Fashion Week.

It's not clear if the Cardi snaps triggered Westhoff ... but she had daggers for Maduka, saying ... “I made you! No one knew who you was. And instead of loving us, you beat me, cheated on me with men and women. You’re a f****** demon who tried to destroy my life.”

Westhoff added there's nothing wrong with being bi ... she's more upset that he's allegedly been MIA in their child's life while he's out partying.

Westhoff did not provide any other evidence on social media to back up her claims. We've reached out to Maduka about the claims but have not heard back.