Opposition Councillors including Mukesh Goel, Prithvi Singh Rathor and Rakesh Kumar charged Gupta with taking money from building owners and allowing "illegal" construction.
They also referred to a list of "illegal" properties constructed with help of Mayor and demanded status report on such properties.
The municipal corporation has formed a committee which would look into the complaints of illegal construction, and 15 days time has been sought for verification of other properties in which complaints have been received, said a senior municipal officer.
"These charges were levelled against me without any proof by the Councillors. They are in the habit of levelling charges against me without any proof," he said.
Claiming that he will step down if allegations were proved, Gupta added, saying the building mafia were trying every trick to cow him down and stop action against illegal construction in North Delhi Municipal Corporation area.