Since becoming president of Angola in 1979, dos Santos has allegedly amassed an incredible amount of money in assets by taking control of several emerging companies and industries.
However, once it was made illegal for the president to have financial holding in companies and organizations by the Angolan Parliament, dos Santos allegedly began arranging for his daughter, Isabel dos Santos, to receive the assets.
According to Forbes, she is Africa's first billionaire and the richest woman on the entire continent.
Human rights groups claimed that Minaj's presence in Angola could be regarded as "an endorsement" of the president's authoritarian rule and have accused the singer of "callously taking money from a dictator".
Minaj was reportedly paid $2million for the performance, where crowd members broke into a chant of her name during the show.
The Grammy nominated rapper shared two videos of the packed audience screaming in pandemonium at the concert to her Instagram account and captioned one video writing: "Angola has my heart."
In addition, she also shared a photo of herself with Isabel dos Santos that she captioned: "Oh no big deal...she's just the 8th richest woman in the world."
Minaj added in the caption: "GIRL POWER!!!!! This motivates me soooooooooo much!!!! S/O to any woman on a paper chase. Get your own!!!! Success is yours for the taking!!!!! #Angola thank u to the women who brought me out here as well."
Prior to the concert, Minaj shared a photo of herself in a sheer bedazzled jumpsuit on Instagram with the caption: "Oh hai, Angola. Ready for the show?"
Minaj arrived in Angola on a private jet and shared a photo of herself disembarking the aircraft in ripped denims and a fur jacket.
She later posted another snap of herself wrapped in an Angolan flag following her controversial performance.
Jeffery Smith, of the Robert F. Kennedy Human Rights centre, said: "Nicki Minaj is following in the footsteps of Mariah Carey, callously taking money from a dictator... who has effectively and ruthlessly choked free expression.
"This sustained crackdown on basic human rights in Angola has swept up activists, opposition members, journalists and even musicians."
Angola marked 40 years of independence from Portugal last month, with dos Santos vowing to bring progress to the country, but critics accuse him of ruling through fear and repression.
In 2013, pop superstar Mariah Carey was similarly criticized for performing in front of the Angolan leader for a reported fee of $1 million.
Human Rights Foundation president Thor Halvorssen also spoke out, saying: "Nicki Minaj is a global artist. There is no good reason for her to do business with the corrupt Angolan dictatorship and endorse the ruler's family company."
Minaj appeared in a Unitel clip on Facebook, promoting the gig and also shared the event's poster via social media, tweeting: "Guess who's performing in Angola Dec 19th at the Unitel Christmas Festival."
The Anaconda rapper will share the stage with local acts at the stadium concert, according to the Unitel website.
