New details emerge about federal investigation into Hunter Biden

The federal investigation into Hunter Biden's business practices is broader than previously known, with multiple sources telling CBS News the probe is exploring whether the younger Biden and his associates violated tax, money laundering and foreign lobbying laws.

Business records reviewed by CBS News and documents released by Republicans in Congress indicate Hunter Biden and his firm were involved in multiple financial transactions with a Chinese energy company called CEFC. Republicans allege that the company is an arm of the Chinese government.

In 2017, the year after Joe Biden left the vice presidency, an official with the Chinese energy company signed a $1 million retainer for Hunter Biden's services as a lawyer.