The head of the American Association of University Professors has accused BP of trying to buy" the best scientists and academics to help it contest litigation after the Gulf of Mexico oil spill. "This is really one huge corporation trying to buy faculty silence in a comprehensive way," said Cary Nelson. BP faces more than 300 lawsuits so far. In a statement, BP says it has hired more than a dozen national and local scientists "with expertise in the resources of the Gulf of Mexico". The BBC has obtained a copy of a contract offered to scientists by BP. It says that scientists cannot publish the research they do for BP or speak about the data for at least three years, or until the government gives the final approval to the company's restoration plan for the whole of the Gulf. And it adds that scientists must take instructions from lawyers offering the contracts and other in-house counsel at BP. What Mr Nelson is concerned about is BP's control over scientific research. "Our ability to evaluate the disaster and write public policy and make decisions about it as a country can be impacted by the silence of the research scientists who are looking at conditions," he said. "It's hugely destructive. I mean at some level, this is really BP versus the people of the United States."