The anti-corruption probe agency opened an investigation into allegations that former Interior Minister Lee Sang-min had ordered fire authorities soon after the December 3 martial law declaration to cooperate to cut off power and water supply to media outlets.

The Corruption Investigation Office for High-ranking Officials(CIO) said on Friday that it had summoned Fire Commissioner Heo Seok-gon as a witness for questioning three days earlier.

The CIO also summoned Seoul Metropolitan Fire and Disaster Headquarters chief Hwang Ki-seok as a witness on Thursday, and Deputy Fire Commissioner Lee Young-pal earlier Friday.

During a parliamentary committee session on Monday, the fire chief testified that the former minister had issued the order during the short-lived martial law to cooperate with the police request to cut off utilities for certain media outlets.