Nines is facing jail after admitting to a plot to import 28kg of cannabis into the UK from Poland and Spain.
The rapper, 31, whose real name is Courtney Freckleton, pleaded guilty on Thursday to drugs and money laundering charges.
He had appeared at Harrow Crown Court in North-West London alongside Jason Thompson, 35.
The pair admitted conspiracy to import the Class B drug cannabis into the UK from Poland and Spain and conspiracy to transfer criminal cash between March 10 and July 3 last year.
The plot involved one successful importation and a second attempted one, with the total amount of cannabis alleged to amount to 28kg, the court heard.
Nines and Thompson both denied two further counts of conspiracy to supply cannabis and conspiracy to supply cocaine and prosecutor Genevieve Reed said prosecutors would not be seeking a trial on the charges.
Ms Reed added that the money laundering charge the pair faced amounted to a £98,000 debt as well as the value of the drugs.
The pair were arrested in June after raids across London and Borehamwood, Hertfordshire with the police operation understood to have originated from the messages infiltrated from the encrypted messaging service Encrochat.
Encrochat had attracted thousands of criminals from around the world but was brought down last year after being hacked by French investigators.
Nines and Thompson are both facing lengthy jail sentences and were remanded in custody by Judge Rosa Dean, with the case adjourned for sentencing.
Nines had previously topped the UK Album Chart with Crabs In A Bucket, his third album which reached number one in 2020, beating Metallica.
He was also named best hip-hop act at the Mobo Awards last year as well as getting the award for album of the year, beating Stormzy, J Hus, Lianne La Havas and Mahalia.