The other three airlines that have been probed in this matter are SpiceJet, GoAir and Air India.
Competition Commission of India (CCI) is currently examining a detailed probe report on the allegations, which was made back in 2013, and is in the process of eliciting views from the concerned parties.
It was alleged that the five carriers acted as a cartel in introducing fuel surcharge for transport of cargo and CCI had ordered an investigation by the Director General (DG) after finding prima-facie evidence of competition norm violations.
The DG, in its report submitted to the CCI in February this year, concluded that there is no sufficient evidence of cartelisation in the case. Now, the regulator is awaiting responses from the concerned parties.
Details of the case have been mentioned by IndiGo in the draft papers filed with capital market regulator Sebi for raising up to Rs.2,500 crore through an initial public offer.
Referring to the case before CCI, Indigo said, "The DG has submitted his investigation report dated February 4, 2015 with the CCI wherein it was concluded that there is no sufficient evidence to conclude the existence of a cartel" under certain sections of the Competition Act.
According to IndiGo, the complainant has filed objections to the findings of the investigation report and a hearing is scheduled to be held later this month.
The complaint was filed by Express Industry Council of India, a grouping of express companies.
"CCI vide its order dated February 19, 2015 directed the informant and opposite parties to appear on April 1, 2015. The informant has filed objections to the investigation report on April 23, 2015 and the matter is now fixed for July 23, 2015 for filing of objections/ rejoinder and arguments," IndiGo said in its Draft Red Herring Prospectus (DRHP).
Among others, the complainant had also alleged that the five carriers were not reducing the fuel surcharge on cargo transportation even when there was a decline in fuel prices.