Vatican City: The Vatican has arrested a Spanish prelate and social media expert for allegedly stealing and leaking classified documents in the second such scandal to hit the secretive institution in three years.

Monsignor Lucio Angel Vallejo Balda, 54, who served on a special commission set up by Pope Francis to advise him on economic reform within the Vatican, was arrested along with a second member of the commission, Francesca Chaouqui, who has been dubbed a “sex bomb”.

The arrests were part of a several months-long investigation into the “misappropriation and disclosure of classified documents and information”.

They followed Italian media reports at the weekend that Vatican police were investigating the attempted theft of a laptop belonging to Libero Milone, the head of the city state’s new finance office, Zee News reported.

Both Vallejo Balda and social media expert Chaouqui, 33, were arrested but she was released by Vatican prosecutor Roberto Zannotti Monday because she agreed to collaborate with investigators and was not considered a flight risk.

Chaouqui’s appointment to the economic committee, which was handpicked by the pope, caused no little embarrassment in 2013 when it emerged the woman dubbed a “sex bomb” by the Italian media had been highly critical of the Vatican on Twitter.

Vatican expert Sandro Andrea Tornielli said today it was Vallejo Balda who got Chaouqui a place on the committee.

A furious Vatican also denounced the expected publication this week of two new books believed to be based on leaks from hackers releasing information regarding the famously murky world of its finances.

And it referred to the last time employees aired the centuries-old institution’s dirty laundry.

In 2012, Pope Benedict XVI’s butler engineered a series of leaks that revealed fierce infighting in the highest echelons of the Catholic Church and allegations of serious fraud in the running of the city state.

Butler Paolo Gabriele was sentenced to 18 months in prison for stealing secret papal memos but pardoned by Pope Benedict, who nonetheless banished the once loyal servant from the Vatican for good.

“As far as the books announced for the coming days go, it is clear that this time too, just as in the past, they are the fruit of a serious betrayal of the pope’s trust,” the Vatican statement said.

It also dismissed any attempts to echo the butler’s excuse that he leaked the information for the pope’s own good.