Real Madrid and Atlético Madrid will be banned from all transfer activity for the next two windows for "irregularities in the signing of minors", according to Spain's Cadena Ser.
The ban will replicate the sanction handed down to Barcelona last summer with both clubs to be charged by Fifa for breaking rules regarding the signing of underage players.
The Spanish radio station reports the two giants of Spanish football will serve the ban in the upcoming summer transfer window and the January transfer window in 2016.
It adds that Real Madrid's recent transfer activity – the signing of Marco Asensio, Lucas Silva, Martin Ødegaard and Danilo – was accelerated due to their impending fear of a ban being handed down.
Fifa rules state international transfers of players under the age of 18 are illegal unless the player in question qualifies for the certain criteria.
"Under-18s can move to a club in a different country if their parents move there for non-footballing reasons, if they are from another nation within the European Union or European Economic Area and aged between 16 and 18, or if they live within 100km of the club."
Barcelona were handed a 14-month ban in April 2014 after being found guilty of breaching such rules.
An appeal process allowed them to proceed with transfer activity that summer however, with the club signing Luis Suárez, Ivan Rakitić, Marc-André ter Stegen, Claudio Bravo and Thomas Vermaelen before the ban was imposed.
Spanish daily Marca claim sources from the Spanish Football Federation have denied Real Madrid's involvement in any transfer irregularities.
Real Madrid have since denied any wrongdoing, describing the reports as 'completely false' in a statement issued through their official website.
"Real Madrid reiterates that the club has always scrupulously adhered to the FIFA regulations, as was explained in detail in the official announcement dated 26 January 2015.
"Real Madrid is once again saddened by these reports, some of which are intended to cause harm, the only aim of which are to implicate the club in supposed infractions that have not been committed."