The police barricaded the area near Mr Mehta's home to prevent Congress workers from reaching his place.
"We want the signature the 'Maha" corrupt minister of Maharashtra, Prakash Mehta, on his resignation letter. For the last two weeks, everyday there is a new scam against Prakash Mehta," Mumbai Congress President Sanjay Nirupam told reporters before being detained by the police.
"Firstly he tried to help a builder benefit by taking the name of the Chief Minister. Now there is an allegation that he has handed over a MHADA plot to a builder. Now there is an allegation that his wife and son are also involved in a SRA project nearby," Mr Nirupam claimed.
The Opposition alleges Mr Mehta favoured a builder in a Ghatkopar transit camp project to help him convert it into a larger slum redevelopment scheme, which would have resulted in a windfall of around Rs 500 crore for the developer.
After the Opposition went on the offensive in the Assembly earlier this week, Mr Fadnavis had announced an inquiry into the project.
Defending himself earlier, Prakash Mehta had said, "The case is entirely political. Congress has no issue left. The case has no facts. The chief minister of Maharashtra himself is looking into this matter."