Pope Francis attends the opening of the Pastoral Convention of the Diocese of Rome at the Vatican June 17, 2013. REUTERS/Stefano Rellandini ROME (Reuters) - A senior Vatican cleric suspected of trying to help rich friends bring millions of euros into Italy illegally was arrested on Friday as part of an investigation into the Vatican bank, police sources and his lawyer said.

Monsignor Nunzio Scarano, 61, worked as a senior accountant in the Vatican's financial administration and is already involved in another investigation by magistrates in southern Italy.

He was arrested in a parish in the outskirts of Rome and taken to the city's Queen of Heaven jail, his lawyer Silverio Sica told Reuters. Also arrested in the investigation were a member of Italy's secret services and a financial broker.

Sica said Scarano was accused of being involved in an attempt to help friends bring 20 million euros ($26 million) into Italy from Switzerland by plane in league with the secret service agent and the financial intermediary.

The lawyer, who had access to the charge sheet, said the money never left Switzerland. Investigators, who were holding a news conference later on Friday, identified the secret service agent as Giovanni Zitto and the broker as Giovanni Carenzio.

It was not clear what role the bank had, if any, in the latest developments.

Vatican spokesman Father Federico Lombardi said in a statement Vatican authorities stood ready to cooperate with the Italian investigation, but had so far received no official request.

He said the AIF, the Vatican's own financial authority, was following the case and would take action if necessary.

The arrests came two days after the Vatican announced Pope Francis had set up a commission of inquiry into the Vatican bank, formally known as the Institute for Works of Religion, which has been hit by a number of scandals inthe past decades.

Scarano worked for years as a senior accountant for a Vatican department known as APSA, whose official title is the Administration of the Patrimony of the Apostolic See.

He was suspended from his duties several weeks ago when he was placed under investigation by magistrates inthe southern city of Salerno, his home town.

In that investigation, Sica said wealthy friends had donated money to Scarano in order for him to build a home for the terminally ill.

According to the lawyer, his client wanted to use that money to pay off his mortgage so he could sell a property inSalerno and use the proceeds to build the care home.

Apparently to cover his tracks, Scarano has been accused of taking 560,000 euros in cash out of his account inthe Vatican bank a little at a time, usually 10,000 euros, and giving it to friends who gave him checks.

He then deposited the checks into an Italian bank account to pay off the mortgage.

($1 = 0.7691 euros)

(Additional reporting by Antonella Cinelli and James Mackenzie, Editing by Mike Collett-White)