It's a mystery worthy of a Dan Brown cracker: a famous religious college on the brink of closure and a locked archive stripped of valuable treasures it hoped to sell to stave off financial disaster.

But the trouble at All Hallows College in Dublin is far from fictional.

The cash-strapped college founded by the Vincentians was targeted by a mystery art thief right up until March this year, the Sunday Independent has learnt.

Even the famous letters Jackie Kennedy wrote to the well-connected All Hallows priest, Fr Joe Leonard, were reported missing to gardai on April 3.