About two years ago I do remember reading the story of a 600+ lbs. catfish cought in the Mekong (sp?) river in Thailand or Nam. 
Here ya go callonetta...this is the beast you were refering to and a brief blurb on the giant.
"Fishers in northern Thailand netted this huge catfish in the Mekong River on May 1. Nearly nine feet long and as big as a grizzly bear, the behemoth tipped the scales at 646 pounds. Experts say the fish, which belongs to the species known as the Mekong giant catfish, may be the largest freshwater fish ever recorded."
Unfortunately, these giant cats are endangered.
