Brazil patents to expire 1 year early?

According to this news item, which is in the process of being picked up elsewhere, a Brazilian Court has decided that, contrary to all conventional wisdom, a patent claiming priority to an earlier application expires 20 years counted from the priority date and not from the date of filing the application. If confirmed, this would be a very surprising development that would presumably affect the lifetime of all priority-claiming Brazilian patents. [UPDATE: See comments below - this case is an unusual one, and the usual rules about priority may not in fact be the issue. There is more information about this issue on IP Tango here, here and here]

The patent itself, which the IPKat presumes is BR9102560, was filed on 19 June 1991 claiming priority to GB9013750.6, filed on 20 June 1990. As far as the IPKat understands, according to Brazilian patent law this means that the patent will expire by 19 June 2011, 20 years from the filing date. However, the Brazilian court has apparently come to a different conclusion and figures that the patent will have expired by 20 June 2010 instead, calculating the 20 year term from the earlier GB priority date instead.

The fact that the patent relates to a pill that tends to be most used by men of a certain age, and which retails for surprisingly large amounts of money in Brazil will, the IPKat thinks, have had no bearing at all on this decision.