Flight 447 – Brazil Says Recovered Debris Not From Jet
June 5, 2009 by national
Filed under Incident Reports

The French government expressed deep disappointment Friday over the news that ocean debris recovered by the Brazilian military this week appeared to be the remains of a shipwreck and not from an Air France jet that crashed in the South Atlantic on Monday.
The revelation came as Airbus, the manufacturer of the missing jet, issued a warning on Thursday to all its customers to follow established procedures when pilots suspect airspeed indicators are not functioning properly. The bulletin appeared to be the first hint that malfunctioning instruments indicators might have played an important role in the crash.
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“French authorities have been saying for several days that we have to be extremely prudent. Our planes and naval ships have seen nothing.”
He said it was “bad news” that the Brazilian teams had been mistaken. “We would have preferred that it had come from the plane and that we had some information.”

I don’t see a reference to any shipwreck in the story you link to. Sailors have been known to toss things overboard and ships have certainly had things spill into the water before. That’s not the same thing as a shipwreck.
And ships have been known to leak fuel and other liquids and leave ’slicks’ of various kinds without the ships being shipwrecked in order to do it.
Can you please link to something that mentions the shipwreck angle more definitively? Thanks.