"We are not happy at all with probe done by the Delhi Police. This is not the way to prove the offence of such serious nature," a bench headed by Justice Aftab Alam said.
Expressing dissatisfaction over the probe, the bench said no progress has been made by the police in more than two years.
"No substantial progress has been made in two years. We are really concerned. Investigation must move fast and it must be brought to its logical conclusion," it said.
The court was hearing a petition filed by former Chief Election Commissioner J M Lyngdoh seeking its directions to the government to take action against politicians involved in the scam which relates the trust vote faced by the UPA government in July 2008.