Competition Commission today said the probe into suspected unfair business practices by around 20 realty players is in progress. Without disclosing specific details, Competition Commission of India (CCI) Chairman Ashok Chawla said the investigation is still under progress. "We are looking at that if there is some formal (or) informal understanding even if they are not dominant. (This part of probe ) is in advance stage," he said at an event here. Among other charges, these developers are being probed for inserting one-sided clauses in favour of the companies and against the interest of consumers in the buyer agreements for sale of flats, apartments and other residential properties, along with other other anti-competitive practices. The CCI has pulled up many realty players in the past for violating fair trade norms. In response to a query on the probe that was initiated against oil marketing companies on petrol pricing, Chawla said the basic point is how the prices move in a similar manner despite being deregulated. "The basic point is that how is it that all of these oil companies increased or decreased the petrol prices (which is otherwise deregulated by the government) almost to the same extent at the same time," he said without divulging specific details.