"I didn't know about (the slush fund) and didn't receive (money)," said Spanish Prime Minister Mariano Rajoy in an interview on Monday with Spanish television station Telecinco.
"I can assure you that neither I nor the party leaders that I know had even the faintest idea about this (slush fund)," he added.
Monday's Telecinco interview saw Prime Minister Mariano Rajoy repeating statements he originally made in the Spanish Parliament in August 2013 after the scandal over the supposed existence of the party slush fund first erupted.
Rajoy made that appearance after Spanish newspapers published documents which appeared to reveal details of payments made from the secret account. After the publication of those documents, former party treasurer Luis Bárcenas went on to claim to have operated the slush fund, even making payment to Rajoy.
Bárcenas then recently restated those claims on his recent release on bail from prison after 19 months in relation to a separate corruption case. The Spanish leader "knew of the existence of the hidden accounts of the PP from the start", said the former money man on his release from Madrid's Soto del Real prison.
But Rajoy on Monday tried to deflect attention from the allegations from the former treasurer.
He told Telecinco viewers he had already provided "many explanations on the subject" but said he understood that people were asking questions.
However, he stressed that the government was working on measures to clamp down on corruption "to ensure that these things don't happen again in the future".
The reemergence of the claims about a secret ruling party slush fund come at a difficult time for Rajoy with general elections set to be held in Spain later in 2015.
Many voters are fed up with a string of corruption high-profile cases involving politicians from Spain's major parties, dissatisfaction which has seen many people saying they will for the country's new anti-austerity Podemos.