During the investigation, the Deputy Superintendence for the Competition Protection found enough evidence that corroborated their participation in a cartel on prices and allocation of quotas for the supply of construction materials extracted from the riverbed. These conducts were carried out from 2011 to 2015.

Last October 2020, the Deputy Superintendent for Competition Protection signed the statement of objections in the case Mineros, and recommended to the Superintendent of Industry and Commerce, Mr. Andrés Barreto, to sanction several mining companies and the Association of Miners of Guamal, Acacías and Castilla la Nueva (ASOMGUACA) for having incurred in practices that restrict free economic competition. During the investigation, the Deputy Superintendence for the Competition Protection found enough evidence that corroborated their participation in a cartel on prices and allocation of quotas for the supply of construction materials extracted from the riverbed. These conducts were carried out from 2011 to 2015. The sanctioning recommendation given would affect 10 of the 12 mining companies, and their legal representatives. Two (2) of the companies under investigation suspended their participation in the cartel, which led to the expiry of the SIC's sanctioning power.

During the investigation stage, the Delegation did not find sufficient evidence to account for the active role of ECOPETROL S.A. in the conduct under investigation. On the contrary, it found elements of judgement that gave an account of the pressure exerted by the miners so that the company's contractors would acquire the construction materials in accordance with the conditions imposed by the mining companies and the association. 

It should be noted that seven companies, together with their legal representatives, applied for the SIC's Leniency Programme before the opening of the investigation. Given the effective collaboration of these agents in the clarification of the facts, the Deputy Superintendent recommended a complete for the first informer, and a partial exoneration for the other informants according to the position assigned at the time they requested to be taken into account as informants.