Twenty years ago this December, the St Jerome, an autographed painting by Michelangelo Merisi da Caravaggio, was stolen from the museum at St John's Co-Cathedral.

Fr Marius Zerafa was then Director of Museums.

The painting was given up as lost for almost two years when Fr Zerafa, a Dominican friar, received a parcel at the priory in late 1986, containing a cassette tape with a recorded ransom demand of Lm500,000, and a polaroid picture of the painting.

Now Fr Zerafa, who has kept a diary throughout his adult life, has published his notes of those events, under the title The Caravaggio Diaries. The book goes on sale today at the Grimand Co. Ltd stand at the Malta Book Fair, in Naxxar. It will be in the shops on Monday.

The Caravaggio Diaries is replete with cryptic, acerbic and amusing asides, typical of its author, and which give a tragi-comic insight into the drama as it unfolded.

Fr Zerafa's account of the repeated failed attempts to trace the calls from "Merisi", the pseudonym used by the man making the ransom demands, is painfully hilarious, though his frustration at these blunders is palpable.

Fr Zerafa tells how Dominic Cutajar, then the dedicated curator of the museum at St John's co-cathedral, tottered into his room at the priory on the verge of collapse, only able to utter the sentence: "Hadulna l-Caravaggio" ("The Caravaggio has been stolen"). Only one custodian had been present, and he was on another floor, when at least two men put up a chain across the entrance to the room where the St Jerome was kept, with a notice saying "Work in progress". They then lowered the painting off the wall and cut it out of its frame.

The thieves had tried to sell the painting in Europe but had failed. "Merisi" began calling Fr Zerafa on a regular basis, demanding money for its return. "Imagine me, a Dominican friar with a vow of poverty and absolutely no sense of the value of money, dealing in thousands of liri, as though I were Henry Ford himself," Fr Zerafa writes.

"Merisi" finally accepted an offer of Lm35,000 - it was clearly a buyer's market - and Fr Zerafa struggled with the powers-that-be for action to be taken in the thick of the most keenly fought general election ever: that of 1987. The minister, however, had his mind elsewhere and was adamant that the Malta police should not be involved in the matter.

This is real life drama at its best but with the inevitable comic twist that comes from what Fr Zerafa calls "ministering to ministers".

The Caravaggio Diaries by Fr Marius Zerafa is published by Grimand Co Ltd (2142 1984).