Mexican Police Arrest Leader of the Gulf Cartel

Mario Cardenas Guillen was detained Monday

(CNN) — Mexican authorities have captured a suspected leader of the Gulf cartel, officials said Tuesday.

A man who "is presumed to be and says he is" Mario Cardenas Guillen was detained Monday in the northern state of Tamaulipas, a spokesman for Mexico's navy told reporters.

His brother, Osiel Cardenas Guillen, was the cartel's founder and former leader. A U.S. federal judge sentenced him to 25 years in prison in 2010 after he pleaded guilty to five felony charges, including conspiracy to possess with intent to distribute, conspiracy to launder money and threatening to assault and kill federal agents.