A senior Vatican cleric, who is under investigation over suspicions of money laundering, was arrested on Friday, for trying to smuggle 20 million euros ($26 million) in cash from Switzerland to Italy aboard an Italian government plane.

Monsignor Nunzio Scarano, 61, had been an accountant in the Administration for the Patrimony of the Apostolic, a key finance office at the Vatican, before he was suspended weeks ago over allegations of fraud and corruption, and was placed under investigation by magistrates in southern Italy.

Scarano’s attorney, Silverio Sica, told Associated Press that the cleric was an intermediary in the operation and was acting on behalf of some friends, who wanted Scarano to persuade a broker, Giovanni Carenzio, in Switzerland to return their 20 million euros.

The lawyer said that Scarano paid an Italian secret service agent, Giovanni Maria Zito, to travel to Switzerland and bring the cash back on a government aircraft. But, the operation failed when the broker went back on his promise to return the money. It is not clear whether Scarano personally went to Switzerland to bring back the money.

However, Zito demanded to be paid 400,000 euros, the commission that was initially promised him, but Scarano only paid him 200,000 euros by check. Zito deposited the check, but Scarano, in an effort to avoid making remaining payment, filed a report for a missing 200,000 euro check, leading to his arrest, according to the attorney.

Carenzio the broker, and Zito, have also been placed under arrest, Sica said. Authorities were already investigating Scarano over suspicions of money-laundering from his account at the Institute for Religious Works, the Vatican’s bank.

In 2009, Scarano withdrew 560,000 euros in cash from his personal Vatican bank account, which accepted donations from people who believed they were funding a home for terminally ill patients in Salerno, a city in southern Italy, and used the money to pay off a mortgage on his home in Salerno.

Scarano told prosecutors that he was not involved in money-laundering, because the money was clean, and that he used the money “temporarily” for personal purposes.

Earlier this month, Pope Francis named a new cleric to manage the Vatican bank, which has been plagued by a series of allegations of money laundering.

The Vatican bank is highly secretive and has refused to co-operate with investigations by Italian authorities in the past. But Pope Francis has ordered an internal investigation showing willingness to bypass the Vatican’s secrecy rules and bureaucracy.