The trafficker, known by the alias "Brother Wang" and with alleged ties to Mexico's Sinaloa and Jalisco New Generation drug cartels, will remain in Cuba awaiting a decision on his possible extradition, the sources added.

Zhang escaped from house arrest in Mexico earlier this year while awaiting extradition to the United States, where a warrant has been issued for his arrest on money laundering charges.

Zhi Dong Zhang is considered "a major international money laundering operator" responsible for "establishing connections with other cartels for the transfer of fentanyl from China to Central America, South America, Europe, and the United States," Mexican Security Secretary Omar Garcia Harfuch said last year.

Washington under President Donald Trump has been applying pressure on Mexico and China to curb drug trafficking, particularly of fentanyl: the powerful painkiller behind an overdose epidemic in the United States.

Fentanyl is a synthetic opioid that is 50 times more powerful than heroin and much easier and cheaper to produce.

It has largely replaced heroin and prescription opioids like oxycodone as a cause of overdoses in the United States.

Although Mexico has been the main source of fentanyl sold in the United States, Washington has increasingly focused its attention on China-based suppliers of precursor ingredients.

Communist Cuba has not officially commented on the reported arrest.