Justice KG Shankar, who had reserved his order last Friday, pronounced the ruling rejecting the bail petitions of both the accused.
The court agreed with the CBI's argument that if released on bail, the accused could influence the witnesses and hamper the probe.
The mining baron and his brother-in-law Srinivasa Reddy had approached the High Court after their petitions were dismissed by the trial court.
They were arrested by the CBI from their home town Bellary in Karnataka in September 2011.
The case relates to illegal mining of iron ore in Anantapur district of Andhra Pradesh by OMC owned by Janardhana Reddy.
Janardhana Reddy is also an accused in cash for bail scam. He is accused of bribing a judge of the CBI court to get bail in OMC case. The Anti-Corruption Bureau (ACB) of Andhra Pradesh last year arrested the judge, his son and several others in the sensational case.
The former Karnataka minister is also an accused in another illegal mining case in Karnataka.