Sinha has been accused of irregularities in the 2G scam probe by an NGO, the Centre for Public Interest Litigation.
Sinha had filed two affidavits before the court refuting the allegations and questioning the petitioner.
The NGO had produced a record of visitors at Sinha’s residence suggesting that some of the scam-accused had called on the CBI chief.
The CBI chief has also told the court that the petitioner is bound by a previous judgement to disclose the source of the visitors' register.
The NGO, represented in court by lawyer-activist Prashant Bhushan, has accused Sinha of protecting some of powerful people accused of links to the scandals.
Image: Central Bureau of Investigation Director Ranjit Sinha