Alexander Smirnov, the former FBI informant who was arrested just eight days ago and charged with lying to the Bureau about Joe Biden and Hunter Biden, has again been arrested, his lawyers state in an emergency court filing Thursday. Smirnov allegedly used Russian intelligence to smear the Bidens, falsely claiming both Joe Biden and Hunter Biden had each accepted $5 million bribes. His claims were the basis of House Republicans’ impeachment investigation into President Biden. But as NBC News’ Tom Winter reported, it’s a “mystery,” at least for now, why Smirnov was arrested again, his lawyers s…