A branch of the Franciscan religious order that runs churches and convents in 110 countries says fraud by some of itsmonks has plunged it into grave financial difficulty.

The Italian news magazine Panorama reported in its latest edition that tens of millions of euros of funds from the Order of Friars Minor (OFM) had been invested in offshore shell companies.

Brother Michael Perry, head of the OFM, said an internal investigation had uncovered "a number of questionable financial activities that were conducted by friars entrusted with the care of the patrimony of the order".

In a letter posted on the OFM website on Wednesday, Perry said the order was in "grave, and I underscore grave, financial difficulty, with a significant burden of debt".

The letter, addressed to all friars, said the order's general treasurer had resigned but gave no details.

Perry could not be reached for comment. His office in Rome said he was not in Italy.

The OFM is one of the four main branches of the Roman Catholic Franciscan order founded by St. Francis of Assisi in the 13th century. The convent and basilica in the central Italian town of Assisi, birthplace of St. Francis, is run by another branch, the Friars Minor Conventual (OFC).