The governor of Bangkok says authorities are investigating why a high-rise building under construction collapsed during an earthquake that otherwise caused limited damage in the Thai capital.

Officers questioned four Chinese men who were found removing 32 files from containers behind the collapsed building, a police official said.

An anti-corruption watchdog had flagged irregularities in the construction of a Bangkok skyscraper that collapsed in an earthquake last week and killed at least 11 people, the head of the monitoring group told Reuters.