MADRID, Oct. 25 (Xinhua) -- The former president of the International Monetary Fund (IMF) Rodrigo Rato entered prison on Thursday to start serving his 4.5-year jail term for the fraudulent use of a "black" credit card during his term as the chairman of the Spanish bank Bankia, the Spanish media informs.

Rato, who was also Spanish deputy prime minister and economy minister in the People's Party (PP) government of Jose Maria Aznar, handed himself in at the Soto del Real Prison north of Madrid shortly after midday.

This happened a day after the Spanish National High Court on Wednesday rejected his appeal for the sentence to be delayed until another appeal against the verdict had been heard at the Spanish Constitutional Court.

Rato was sentenced to four and a half years in jail by the Spanish National Court on Feb. 23, 2017 for the use of so-called "black" credit cards with which he and 63 other former directors of the bank were found guilty of spending 12.5 million euros (14.28 million U.S. dollars) from Bankia (and in its previous guise as Caja Madrid) during the period 2003 to 2012.

The court found that 69-year-old Rato and other directors were issued with personal credit cards which they were able to use at their discretion, with none of the money ever being declared as earnings for tax purposes.

The uses of the card varied from restaurant bills, the purchase of jewelry and fine wines, a safari, suits, perfumes, to simply taking cash from ATM machines. Meanwhile among Rato's total expenses of 99,041 euros, were 3,547 euros spent on alcoholic drinks in one day.

The court accepted the finding that the money spent on the "black" cards was not reflected in the contracts the accused had with Bankia and did not appear in tax declarations.

"Those who received the cards were not obliged to use them. If they did, that implied they accepted their participation in the plan that was offered to them," the Supreme Court judges found.

They said it was not possible to accept that Rato and his companions could believe they had acted "in accordance with the law in using the bank's money for their personal use or for any kind of expenses without any means of control or it being reflected fiscally."

They also agreed that when Rato became Bankia chairman in 2010, he "maintained the system and indeed extended it to other people."

Rato resigned as Bankia president in May 2012 when it was announced the bank required a Spanish government bailout of around 20 billion euros.