If you are looking for someone who can move capital markets, try Haroldo Lima, former electric engineer and Brazilian Communist party lawmaker, and, since 2005, director of the ANP, Brazil’s energy regulator. On Monday Mr Lima said 400km offshore from Rio de Janeiro, under a layer of salt, could lie the third largest oil field in the world. His comments added more than $20bn to the market value of the companies involved, including Petrobras, Repsol, Hess and BG Group. The provenance of Mr Lima’s opinion does not appear authoritative. Attempts by the ANP and Petrobras to clear up the confusion have proved singularly ineffective. An optimistic interpretation is that Mr Lima thinks the Sugar Loaf prospect, which covers several licence areas, or “blocks”, could contain an incredible 33bn barrels of oil equivalent of recoverable reserves. Just an off-the-cuff remark by a regulator? Not quite. Petrobras says no new seismic data exist but 33bn boe is far above most third-party estimates – Morgan Stanley, for example, had assumed about 15bn boe. Furthermore, Brazil has recent form: in November, the adjacent Tupi field was found to have 5-8bn boe of recoverable reserves.

Apart from Petrobras, which companies might benefit most is debatable. Europe’s Repsol, BG Group and Galp own stakes in blocks on the edge of Sugar Loaf while Exxon and Hess may have better positioning. For Brazil itself, the discovery would be politically important, taking it from the world’s 16th largest to seventh largest country for oil reserves, just behind Russia. It is early days but, with exploratory drilling due by BG in the summer, Hess and Exxon in the second half of the year, and BG again next year, Sugar Loaf’s true size should become clear soon. Investors and Brazilians, as well as the temporarily omnipotent Mr Lima, will hope his comments prove to be right.