Switzerland is considering a US extradition request for a Russian businessman detained in the wealthy Alpine nation and suspected of large-scale insider trading, the Swiss justice ministry said Tuesday. The Federal Office of Justice confirmed Swiss media reports that Vladislav Klyushin had been arrested in the canton of Wallis in March. On April 19, the US embassy in Bern requested his extradition, accusing him of "running insider trading in the tens of millions (of dollars) with several accomplices", a justice ministry spokeswoman told AFP by email. Klyushin has opposed the US extradition request, she said. According to Russian opposition media, the businessman was very close to senior Kremlin official Alexey Gromov. He reportedly heads several companies, including the M13 group which specialises in IT solutions for media monitoring and cyber-security consulting. The Russian businessman had appealed to Switzerland's federal court to lift his detention, but the court rejected his request last month. The Swiss judiciary must now decide whether or not to grant the US extradition request. Both sides will have the right to appeal against the outcome. bur-apo/nl/rjm/jj