Rapper Nas and his R&B singer wife Kelis are reportedly threatening to launch a $100 million lawsuit against the city of Miami, Florida accusing officials of racial profiling.

Milkshake hitmaker Kelis - real name Kelis Rogers-Jones - was arrested in the city in March last year for allegedly screaming racial obscenities at two undercover police officers.

She was charged with two misdemeanour counts of disorderly conduct and resisting arrest, and was later released on a $1,000 bail bond.

Kelis’ husband Nas - real name Nasir Jones - was reportedly talking to the undercover cops at the time of his wife’s arrest.

And now the couple are said to be planning to sue city officials over claims they were unfairly targeted by police, according to MediaTakeOut.com.

A source tells the website, "Kelis has been silent about everything thus far. She’s waiting for the right time and then she’ll explain exactly what happened."