A company backed by two of U.S. President Donald Trump’s sons reportedly invested in a mining group that is developing a $1.1 billion tungsten project in Kazakhstan, Financial Times has found. According to FT, both Donald Trump Jr. and Eric Trump have been using a shell company to buy stakes in U.S. construction group Skyline Builders (Nasdaq: SKBL), which on Thursday merged with Cove Kaz Capital Group, the unit of New York–based mining investment group Cove Capital that was awarded the tungsten project last year.