Rapper Soulja Boy has filed a lawsuit against his former manager, alleging he was coerced into signing "unconscionable, oppressive, and unjust" contracts.

The Crank That (Soulja Boy) hit-maker claims Philip Ransom made him agree to documents which gave the manager/lawyer five per cent of his income and awarded 50 per cent of his music copyrights to his record label.

The star is adamant the deal is "commercially unreasonable" and "contrary to music industry custom and practice," and he's filed papers against Ransom in Georgia Superior Court.

Ransom has denied the allegations and filed his own papers against Soulja Boy, alleging he is owed money from his time as an employee of the star, according to TMZ.com.