A prominent human rights group is urging American hip-hop artist Nicki Minaj to cancel her upcoming performance in Angola for a company linked to the country’s dictator.

In a letter to Minaj, Thor Halvorssen, president of the Human Rights Foundation, wrote that, "the payment you are receiving from your Angolan sponsors is the result of government corruption and human rights violations." She is scheduled to perform on Saturday in the southern African nation at a Christmas festival sponsored by Unitel, a phone company owned by the daughter of Angolan dictator José Eduardo dos Santos.

Halvorssen writes:

During their brutal three-decade authoritarian rule, the dos Santos family has exploited Angola’s diamond and oil wealth to amass an illegitimate fortune while maintaining control over all branches of the government, the military, and civil society. Dos Santos has made it his policy to harass, imprison, or kill politicians, journalists, and activists who protest his rule. In Angola, independent media are subject to systematic legal and physical persecution. Journalists are routinely arrested, beaten, and even disappeared when covering corruption matters and exposing the dos Santos criminal enterprise. Beyond censoring through violence, the Angolan regime owns the only national radio station, controls the only daily newspaper, and exerts control over Angola’s television stations. Artists such as yourself are not allowed to freely express their opinions in Angola, where criticizing the government is a crime punishable with fines and imprisonment.

He added that several nonviolent activists, including one hip-hop star, have been persecuted in Angola:

The dos Santos regime’s ongoing crackdown on dissent is well illustrated by a current trial against 17 peaceful activists in Angola. The 17 individuals, including Angolan hip-hop and rapper star Luaty Beirão, were arrested and detained in June 2015 in the city of Luanda after attending a meeting to discuss democracy and non-violence. Specifically, they discussed Gene Sharp’s book "From Dictatorship to Democracy," a guide to nonviolent resistance. These activists were jailed for more than 90 days without being formally notified of the charges they were facing. And now they will be tried on charges of plotting to overthrow the Angolan government.

Other famous American artists, including Jennifer Lopez and Kanye West, have also been criticized for performing at events sponsored by autocratic regimes.