Argentine police on Tuesday arrested former Public Works Secretary Jose Lopez after throwing "an obscene amount of cash" over the walls of Our Lady of the Rosary of Fatima monastery outside the capital.

Authorities discovered luxury watches and over $7 million (6.24 million euros) in cash, said Dario Kubar, the mayor of General Rodriguez, where Lopez was arrested.

However, Buenos Aires provincial security chief Cristian Ritondo said police were still counting the cash, which included "dollars, yen, euros and a currency from Qatar."

"He tried to bribe one of the officers, and the bribe was rejected," Ritondo said. "He later told the nuns that police tried to steal the money that he was trying to donate."

Lopez served in the former government of President Cristina Fernandez de Kirchner, who prosecutors in May charged for defrauding the state.

"We found an obscene amount of cash at the convent, where neighbors and even the nuns living there told us that a lot of officials from the previous government had visited," Ritondo added.

'Serious corruption'

Cabinet chief Marcos Pena told reporters after the arrest that Lopez "has to explain" how he obtained the cash.

"Lopez managed everything that had to do with public works under the previous government. This confirms there were enormous problems with transparency, at least, and at most, serious corruption," Pena said.

Argentine President Mauricio Macri, who campaigned on an anti-corruption platform, described the incident as "shameful."

"We are all surprised. We are clearly changing and it's good that we shed light on the type of practices that we want to eradicate in Argentina," Macri said during a public event.

During his inauguration speech in December, Macri vowed to root out corruption by empowering prosecutors to investigate graft in public offices.

ls/kl (AP, Reuters)