
Workers had been hired to fit out "survival" containers with doors, windows and air conditioning
The man, identifying himself as Teacher Wang, said Taiwan would be struck by a magnitude-14 earthquake and 170m (560ft) high tsunami on 11 May.
More than 100 cargo containers have been bought and set up in a mountainous area of central Taiwan.
Police said they were investigating if the blogger had conspired with a container business to defraud people.
"Teacher Wang" suggested people live in such containers to survive the disaster, which he said would kill millions of people and split the island in half.
'Hide my face'
Taiwan's famous Taipei 101 skyscraper and the Presidential Office building would be toppled, he warned.
More than 100 cargo containers have been discovered in the town of Puli, Nantou county.
Workers had been hired to fit them with doors, windows and air conditioning, says the BBC's Cindy Sui in Taipei.
The containers cost about $5,500 (£3,300) each, once water and electricity are included, our correspondent adds.
Taiwan is in a quake zone. In 1999 a 7.6-magnitude tremor killed more than 2,400 people and damaged 50,000 buildings.
But Taiwan's Central Weather Bureau says there is no basis for the doomsday prediction, since a magnitude-14 tremor is unheard of, and quakes cannot be reliably predicted.
Officials say Japan's recent devastating quake and tsunami may have led fraudsters to exploit people's fears.
The police have not been able to trace "Teacher Wang", who had touted his theory to TV reporters but insisted his face not be shown.
The authorities have removed his doomsday warnings from the internet.
Fraud convictions carry a maximum five-year jail term while breaking the law on social order is punishable by a fine of up to $1,000, said Taiwanese police.
Its 11pm in Tiawan, May 11th 2011 and no Earth Quake
Need I say more?