CBI sources said Singh was quizzed early this morning, while Javadekar arrived at 1.45 PM at the agency headquarters for questioning.
"I believe in the legal processes. CBI has called me today so I have appeared here," Javadekar told reporters.
CBI has also summoned party general secretary Ramlal who also figured in the sting operation relating to the Tulsiram Prajapati alleged fake encounter case conducted by an independent journalist .
In the sting operation, the leaders are purportedly shown discussing how Prajapati's mother Narmadabai can be convinced to change her Vakalatnama.
Also Read
She has filed a case alleging her son was killed in a fake encounter in which BJP general secretary Amit Shah is an accused.
However, BJP has claimed there is nothing "incriminating" against the three leaders in the sting operation.
Prajapati, who was allegedly a witness to Sohrabuddin Sheikh's murder, was killed on December 2006--a year after Sheikh was shot dead in an alleged fake encounter in Gujarat.