IRS whistleblower alleges mishandling of Hunter Biden tax investigation.

An unnamed IRS criminal supervisory special agent has requested whistleblower protections from Congress to speak out about allegations that the Hunter Biden tax investigation has been hindered by "political considerations," according to a letter obtained by CBS News. The agent's attorney claims that the investigation has been handled differently from any other investigation in his lengthy career with the IRS. The agent has extensive documentation to back up his claims, and his information would "contradict sworn testimony to Congress by a senior political appointee."