InSightcrime.com has published that some 300 cases of fuel theft are currently being prosecuted in Cuba with the provinces of Havana, Villa Clara, and Holguín accounting for the highest number of cases.
The investigative site says the problem has been aggravated by sanctions on its principal supplier, Venezuela.
It reports estimates by the Electrical Union of Cuba, that almost 2.5 million liters of diesel disappeared from the Santa Fe power plant in Guanabacoa on September 4. The site links the problem to severe oil shortages and the high cost of the commodity.
Earlier in May, The New York Times reported that the Cuban government has begun widespread rationing.
Commerce Minister Betsy Díaz Velázquez was quoted as saying the hardening of the American trade embargo by the Trump administration was the cause.
Otherwise, the news site quoted economists who have blamed a reduction in aid from Venezuela.
In Venezuela, the collapse of the challenges facing the state-run oil company has resulted in supplies to Cuba being cut by two-thirds.
The reduction in oil supply has also affected production in the island.