Mexican marines have arrested Mario Cardenas Guillen, a suspected leader of the Gulf drug trafficking cartel.
Mr Cardenas Guillen, alias El Gordo or the Fat One, was arrested in Altamira in the northern state of Tamaulipas.
Officials say he headed a faction of the cartel, which split in 2010 after his brother Antonio Ezequiel was killed in a shootout with marines.
The Gulf Cartel has been engaged in a bloody battle for trafficking routes with the Zetas drug gang.
Mario Cardenas Guillen was paraded before the media on Tuesday, a day after his arrest, flanked by two masked and heavily armed marines.
He was "one of the main leaders" of the Gulf Cartel, navy spokesman Jose Luis Vergara said.
Mr Cardenas Guillen's high-profile arrest comes just months before President Felipe Calderon, who launched a crackdown on the cartels in 2006, ends his term in office.
Over this period, a number of key cartel leaders have been killed or arrested.
"This is certainly a big hit to the cartel, but historically new leaders are tapped very quickly," Vicente Sanchez, a security researcher with the Northern Border University in Tijuana, told Reuters.
The Gulf Cartel was led by a Cardenas brother, Osiel, until his arrest in 2003. He is currently serving 25 years in the US.
in 2010, Antonio Ezequiel Cardenas Guillen, who was known as "Tony Tormenta" and was one of the gang's top leaders, was killed in a shootout with Mexican troops.
The Gulf Cartel then split, officials say, with Mario Cardenas Guillen heading one faction and rival leader Jorge Eduardo Costilla another.
The Gulf Cartel has been weakened since 2010 when relations were severed with its former enforcers, the Zetas, who are now one of Mexico's most powerful drug trafficking organisations.