Krishnankutty and Anarkali, in whose name the licence for the fireworks display had been taken, were picked up from Pallickal here, police said.
The woman was the third accused while her husband the fourth accused, they said.
The two had been absconding since the devastating mishap during the festivities at the Puttingal Devi temple on April 10, which claimed 108 lives and left over 300 injured.
The couple has moved an anticipatory bail petition in the Kerala High Court saying they had been conducting the fireworks display for the past 40 years with proper licence that was valid till March, 2017.
So far, twenty five persons, many of them workers employed by the contractors, have been arrested in connection with the incident during the fireworks display that went awry.
Police have registered cases for offences including attempt to murder against the accused.