The former President of the Republic of Portugal, Cavaco Silva, was born and raised in the Algarve and in 1997, bought a plot of land on which to build a house.
The plot already has planning permission based on a project submitted to the council in 1994 but, being a man of some wealth, Cavaco Silva built a house of almost double the original project size in Aldeia da Coelha, Albufeira.
When it came to the rateable value, the Valor Patrimonial (VP), the figure was dervived from the smaller sized project - a house that was never built.
The politician then was happy to pay a much reduced rates bill for fifteen years based on his submission in 2009 that took the original incorrect and cheaper VP of €199,469.
The property was re-rated last year at €392,220.
Público, a Portuguese daily, sent the details off to several specialists, not naming the president as the owner of the property, asking their professional opinon as to how the incorrect submission affected the payments and how this situation could have come about.
One thing is for sure, the 2009 submission was wrong: whether the president submitted the lower figure dishonestly or whether it was a genuine mistake, we probably will never know.
The taxman can send the former president a bill for the underpayments, but not for the full 15 years during which Cavaco Silva paid far lower rates that he should have done. Normal citizens also would receive stiff fines for the years of 'error'.
The former president has not responded to polite enquiries on the matter.