Kolkata, June 1 -- A senior official of the state government's Agriculture Marketing Department sustained serious injuries after allegedly falling through a staircase gap inside Khadya Bhavan in central Kolkata on Monday morning, prompting an investigation by the police.

According to sources, the incident took place between 10:00 and 10.30 a.m. The injured official, who is serving as a Joint Secretary in the department, reportedly fell from the upper floors of the building and landed on a lower staircase landing.

Office employees who witnessed the aftermath said they had just started their workday when they heard a loud crashing sound from inside the building.

"We suddenly heard something fall with a thud. When we rushed to the spot, we ...