Samajwadi Party MP Rewati Raman Singh today appeared before Delhi Police for questioning in connection with the 2008 cash-for-vote scam. He is the fourth person to be quizzed in the past 10 days after the Supreme Court came down heavily on investigators for carrying out a shoddy probe. The questioning of Rewati Raman comes three days after his former party colleague Amar Singh was questioned by the investigators. Two persons Sanjeev Saxena, former aide of Amar Singh, and Suhail Hindustani, an alleged go-between Amar Singh and BJP sought to be bribed, were arrested after quizzing.