Two men who used to run a Vatican-owned children's hospital have gone on trial, accused of diverting nearly half a million euro of funds to renovate a top cardinal's apartment.

Giuseppe Profiti and Massimo Spina, respectively the former president and treasurer of the Bambino Gesu hospital in Rome, are charged with spending €422,000 in 2013 and 2014 on refurbishing the large Vatican apartment of Cardinal Tarcisio Bertone, the Vatican's former number two.

The trial was adjourned until 7 September, and the court left open the possibility that Cardinal Bertone, who was not indicted, might be called as a witness.

Cardinal Bertone, 82, was the Vatican secretary of state for most of the pontificate of former Pope Benedict and was one of the most powerful men in the Catholic Church.

He was removed from office in 2013, eight months after the election of Pope Francis.

The renovation started a few weeks later on the property, which is next door to the Vatican guesthouse.

The trial began with the court rejecting a defence motion to dismiss, as well as a request from lawyers for the defence asking that journalists be barred from future hearings.

Mr Profiti and Mr Spina risk prison sentences of three to five years if convicted, under Vatican laws on conspiracy to commit a crime and misappropriation of funds.

When the Vatican confirmed last year that Mr Profiti and Mr Spina were under investigation, a lawyer for Cardinal Bertone said the cardinal had never asked for, or authorised, payment for the restoration work from hospital funds.

Mr Profiti has said the hospital used its funds to renovate Cardinal Bertone's apartment because the cardinal had agreed that it could be used for fundraising.

Hospital officials said at the time that Cardinal Bertone had given €150,000 of his own money to Bambino Gesu to make amends for damage done to the hospital's image.