Robert Abela failed to give "clear answers" about the context of a conversation with a magistrate about sentencing policies.
A probe into whether the prime minister had breached the code of ethics by having the conversation was triggered following complaints by independent candidate Arnold Cassola and law student organisation GħSL.
During a political activity in Birkirkara in January 2023, the prime minister had recalled how he met a magistrate who expressed frustration about how tough punishments get watered down on appeal.
“They told me that while the law allows them to give harsher penalties, experience has shown that the guilty party is likely to file an appeal. The chances are that the court of appeal will reduce the penalty as a result of previous sentences which leaned in that direction," he had said.
His admission about the conversation drew condemnation from ADPD and Repubblika, who said it impinged on judicial independence.
The chamber of advocates also issued a statement saying such conversations violated the judicial code of ethics.
In a decision on Friday, standards commissioner Joseph Azzopardi said informal conversations between members of the government and the judiciary are not "desirable".
He said all dialogue between the judiciary and members of the executive should take place through official channels.
The standards commissioner said the context of how this conversation started is key in this particular case, as it is one thing if the pair bumped into each other at a social event, and another if one party initiated contact specifically to discuss sentencing policies.
Azzopardi said he was unable to conclude if the prime minister had breached the ministerial code of ethics in this case, as Abela had failed to give "clear answers" about how the conversation came about.
The prime minister argued in a letter to the commissioner that he had a duty to speak out during his January 2023 speech in the wake of a "shocking homicide" in Gżira.
His speech came after Pelin Kaya was mowed down by a car driven by Jeremie Camilleri, who has since admitted to murder.
The prime minister denied speaking to the magistrate about a specific case, claiming that the conversation was about general policies and procedures in court.
Abela said the conversation in no way impinged on the concept of separation of powers between the judiciary and government.
A probe by the data commissioner was unable to find any document or record of the conversation, following a freedom of information request filed by Cassola.