Rajoy appeared in Spanish Parliament on August 1st to answer questions about a PP slush fund allegedly operated by ex-treasurer Luis Bárcenas.
During that appearance, the Spanish leader said the official had stopped working for the party before he became Prime Minister in December 2012.
But Spain's El Mundo newspaper on Sunday published PP payslips it said showed Bárcenas had received 14 payments of €18,297 ($24,380) after this date.
The daily said the former treasurer had remained on contract to the party.
Bárcenas was the best paid PP leader in 2011 and 2012 the paper also reported on Monday.
In 2011, he was paid €219,000 while in 2012 he received €251,000.
In July, Bárcenas, said he handed €25,000 ($33,000) in 500-euro notes to the Prime Minister in March 2010.
The former PP treasurer is currently in prison without bail because of his involvement in another corruption scandal, known as Caso Guertel.
He had failed to explain millions of euros held in Swiss bank accounts, judges involved in that case said.