However, La Mancha Negra reappeared in 2001 on several roads in Caracas, including Baralt, Nueva Granada, Fuerzas Armadas, Sucre, and Urdaneta Avenues.
[2][5][4] A team of the Venezuelan Ministry of Transport and Communications believed La Mancha Negra was composed of dust, oil, and various organic and synthetic materials.
[6] In 2001, The Sunday Telegraph stated that one report showed it "was a mixture of used engine oil and highly corrosive brake fluid", but concluded that "After 14 years of study, no one knows what the stuff is, where it comes from, or how to get rid of it".
Venezuelan engineer and official Fernando Martinez Móttola stated in 1991 that he would not only remove La Mancha Negra but also the residents near the Caracas-La Guaira highway since "they were part of the problem by creating leaks in the road".
[2][7] Professor Giannetto, a commissioner of the Ministry of Transport and Communications, believed that La Mancha Negra was an accumulation of dust and oil released from cars that formed a paste on the roads.
[6] In 1996, The Wall Street Journal reported that "due to the cheap gasoline prices in the country, Venezuelans would drive dated gas guzzlers, stating 'Locals call the highway "la mancha negra," or the black stain, because it literally shines with the oil drippings of thousands of big cars that labor up an incline into the city each day.'
[8] In 2001 following Hugo Chávez's Bolivarian Revolution, the substance was used as a political tool once more, with chavista mayor Freddy Bernal stating that the opposition had hired homeless Venezuelans to spread it from plastic bags during the night.