Spanish Prime Minister Mariano Rajoy, who faces allegations he received under-the-table payments from a purported Popular Party slush fund, on Saturday released income statements that show he received net income for his work of 74,912 euros (roughly $100,100) last year.

That figure is roughly half of the net income of 147,620 euros ($197,272 at the current exchange rate) he received in 2004 as a lawmaker and the PP's chairman.

Rajoy's final after-tax income in 2012 amounted to 49,893 euros (roughly $66,674), according to one of the documents posted to the Spanish government's Web site.

The release of the returns comes amid a major scandal caused by the publication late last month by leading Spanish daily El Pais of extracts from a purported secret ledger that appears to show two decades of off-the-books cash payments to party leaders, including Rajoy.

The premier has categorically denied that he or other PP leaders received any under-the-table payments, but he has ordered an internal review of PP finances and commissioned an examination by independent external auditors.

Spain's attorney general, Eduardo Torres-Dulce, told reporters Thursday there are grounds for further investigating the allegations.

Former PP treasurer Luis Barcenas, who is at the center of the scandal, denied the existence of secret accounts in statements to prosecutors this week and said he was not responsible for the handwritten ledger that has been attributed to him.

He also provided a handwriting sample that is to be compared and contrasted with the documents published by El Pais.

So far, prosecutors have not linked the probe of the ruling party's finances to recent revelations that Barcenas had deposited some 22 million euros (roughly $29.5 million) in Swiss bank accounts. EFE