According to ANI, CBI laid a trap and caught him red-handed while taking a bribe to settle a tax evasion matter. Subsequently, he was immediately taken to CBI headquarters for questioning and formally placed under arrest.
No involvement of Sisodia in the case has surfaced so far and the investigation is going on, sources said.
As per the Delhi government website, Madhav was appointed as an OSD to the Deputy Chief Minister in 2015.
Hours after Madhav's apprehension, reports came in of his close aide Dheeraj Gupta also being arrested by CBI sleuths. As per ABP News' Sources, Gupta was held on February 5 itself and used to work as a broker for several officers.
Meanwhile, Deputy Chief Minister Manish Sisodia on Friday said Gopal Krishna Madhav should be punished immediately.
In a tweet in Hindi, Sisodia said, "I have came to know that the CBI has arrested a GST inspector for taking bribe. This officer was also posted as an OSD (Officer on Special Duty) in my office".
"The CBI should get him the strictest punishment immediately. I have got several such corrupt officials caught in the last five years," he added.
Delhi is going to polls on February 8, while the results will be declared on February 11.
(With Agency Inputs)