BOGOTA, Colombia (AP) — U.S. prosecutors say Venezuela's former oil czar received bribes as part of a major graft scheme that allegedly took place in the OPEC nation's oil industry, an American official familiar with the probe said.

Rafael Ramirez, who was one of Venezuela's most powerful officials until he quit as the country's U.N. ambassador in December, was named as a bribe recipient although he was not charged in an indictment against five other former senior officials that was partially unsealed Monday.

In the indictment, prosecutors in Houston allege two of the charged individuals told...