A cocaine shipment seized by Mexico last week could have been worth as much as $2.7 billion on U.S. streets and the Mexican government said on Monday it belonged to Mexico's most wanted man, drug lord Joaquin "Shorty" Guzman.

Police, navy and customs officers found the 23.5 tons of drugs hidden in a shipment of plastic floor-covering aboard a Hong Kong-flagged container ship at Mexico's Manzanillo port on the Pacific. The vessel came from Colombia and the drugs haul was the biggest ever seized by authorities, Mexico said.

"This is the world's biggest cocaine seizure ... and we believe it belonged to the Pacific cartel," Attorney General Eduardo Medina Mora told reporters, referring to the drug gang that Guzman leads and that U.S. officials call the Sinaloa consortium.

U.S. Ambassador to Mexico Antonio Garza put the value of haul at $400 million. But the U.S. government said last month the average price of the drug on U.S. streets had risen to $118.70 per gram in the first six months of the year. That would give the Mexican haul an implied street value of some $2.7 billion.

The Sinaloa alliance of drug gangs on Mexico's western coast is considered the country's most powerful cartel. Guzman, who escaped from a maximum-security jail in a laundry van in 2001, has so far eluded massive army and police searches for him.

The 23.5-ton seizure doubles the Mexican record, set only last month when soldiers found more than 11 tons of cocaine at the port of Tampico on the Atlantic coast, home to Guzman's main rival, the Gulf Cartel.

Some 4,500 people have been killed in Mexico in the last two years, mainly due to a turf war between the Gulf and Sinaloa cartels.

Mexico has seized a record 48.4 tons of cocaine so far this year, worth at least $1.5 billion, the government said.