A former Seberang Perai municipal councillor wants the MACC to investigate the "big shark" involved in graft activities at the Penang Road Transport Department (RTD) instead of merely hauling up the "small fry".

Teoh Seang Hooi, who also heads the DAP Bukit Tambun branch, wants to know who is the "godfather" behind the 52 RTD enforcement officers who were detained by the Penang MACC since April 20.