Rana sought 14-day custodial interrogation of the accused, saying it was required to trace the trail of proceeds of the crime and complete the investigation.
"I am not allowing the food application as I am sure that they will take good care of it," the judge said.
Singal was placed under arrest on Friday, under the Prevention of Money Laundering Act (PMLA), after he was questioned in connection with the case.
Hewas arrested as he was not cooperating in the probe, the agency charged.
The ED recently attached assets worth Rs 4,025 crore of Bhushan Power and Steel Limited (BPSL).
Advocate A R Aditya, also appearing for the ED, said, "An amount of Rs 695.14 crore was introduced as capital by Sanjay Singal (the then CMD of the company) and his family members in BPSL out of artificially generated long-term capital gains (LTCG) by diversion of bank loans fund of BPSL.