The Moroccan king has promised an investigation into the royal pardoning of a Spanish man convicted of raping 11 children aged between four and 15.
The paedophile was among 48 jailed Spaniards freed by King Mohammed VI, sparking angry protests and violent clashes with police in Rabat on Friday.
A royal statement said the king had been unaware of the gravity of the Spaniard's crimes.
Fresh protests are expected in Casablanca and Rabat next week.
Daniel Galvan Vina, believed to be in his sixties, was sentenced to 30 years in prison in September 2011.
However, last week he was freed by royal decree from a jail in Kenitra, north of the capital. He is reported to have left the country.
Dozens of people were injured in violent confrontations between hundreds of protesters and police outside parliament in the Moroccan capital on Friday.
Demonstrations were also reported in the cities of Kenitra, Tangier and Tetouan, as well as outside the Moroccan embassy in Paris.
"The king was never informed - in any way or at any time - of the seriousness of the abject crimes of which the person concerned was convicted," a statement released by the royal palace said on Sunday.
"It is clear that the sovereign would never have consented" to his release, given the "monstrous crimes" committed, the statement concluded.
It is normal procedure for the king to pardon prisoners on special occasions, such as Throne Day, last Tuesday.
Morocco's Justice Ministry said on Friday the pardons were based on national interests and "friendly relations" with Spain.
A number of foreign nationals have recently been detained in Morocco under suspicion of paedophilia.
In June, a British man was arrested in the port town of Tetouan over allegations of raping a six-year-old girl. In May, a Casablanca court sentenced a French man to 12 years in jail on paedophilia charges.
Thousands of Moroccans marched in Casablanca earlier this year to condemn paedophilia and violence against children in the north African country.