(Bloomberg) — More than a month since oil started washing up on some of Brazil’s most touristic beaches, dotting sand with black patches, killing sea turtles and scaring off fishermen, the origin of the crude is still a mystery. “We don’t know the oil’s origin, where it came from or how it got here,” Energy Minister Bento Albuquerque said at an offshore exploration auction in Rio de Janeiro on Thursday. The crude probably leaked from a ship in the ocean, he ventured, adding that it has characteristics similar to Venezuelan heavy crude — which doesn’t mean it comes from there.