Sources said that the questioning followed legal advice tendered by the Advocate-General that former HC judges could be questioned without prior approval of high court or the supreme court. 

The names of Justice K Thankappan and Justice K Narayanan Kurup had cropped up in the recent revelations by K A Rauf, a former close aide of IUML general secretary P K Kunhalikutty who turned against him. Rauf had alleged that he had personally seen bribe being passed on to Justices Thankappan and K Narayana Kurup through their aides or relatives at the behest of Kunhalikutty for issuing favourable verdicts.

According to police five complaints have been made out against Justice Thankappan. They include giving favourable verdicts on the petition of the accused for shifting the trial court, changing prosecutor, in camera trial and evidence regarding the age of one of the victims Regina.

Though the crime branch had sent notices to the judge three times, he did not accept it twice and the third time he wrote back saying that he could not be questioned without prior approval of the court.