A US Senator has called on the Department of Justice to investigate an alleged fraud by ExxonMobil over what it knew and told the public and shareholders about the cause of climate change. Senator Bernie Sanders has written to Attorney General Loretta Lynch to ask for a probe into what he alleges as a "potential instance of corporate fraud" by the oil giant. In his letter the politician refers to reports from an investigation by Inside Climate News, which says that scientists from the company conducted extensive research on climate change as early as the 1970s. According to the reports, the company's staff found climate change was real and partially cause by carbon pollution from petroleum products. ExxonMobil has hit back at the claims and said scientists continue to research and publish findings to improve understanding of climate system science as a basis for society's response to climate change.