The rapper was to play a concert in Angola on New Year's Eve 2011, but backed out without explanation at the last minute.
Event promoter Patrick Allocco was then taken at gunpoint by local 'concert impresario' Henrique 'Riquhino' Miguel, who demanded the rapper's $300,000 (£194,000) advance back as well as £50,000 (£32,000) in expenses.
The rapper refused to pay, which Allocco claims led to him being held captive for 50 days. He also says that he was beaten and threatened constantly during his time in captivity.
Now TMZ reports Allocco is suing Nas for $10m, alleging that he suffered psychologically, physically and financially during the ordeal.
He also claimed that while stuck in Angola he was unable to do business, and as a result lost his home and his company.
Nas is yet to comment on the lawsuit.
Watch the video for Nas's 'The Don' below: