Former Finance Minister P Chidambaram, who is in Enforcement Directorate custody, was on Monday rushed to AIIMS after his health dipped.
A court had earlier ordered that the Congress veteran would stay in the agency's custody till October 30.
Chidambaram has been juggling between CBI and ED since August when he was arrested for his role in the INX Media case.
Why are ED and CBI investigating Chidambaram?
The veteran leader is accused of facilitating the influx of illicit FDI into INX Media when he was at the helm of the Finance Ministry.
His son Karti, a Congress MP from Sivaganga, is accused of forging a deal with founders Peter and Indrani Mukerjea in return for kickbacks.
Naturally, Chidambaram's arrest was dubbed as "political vendetta" by Congress.
Earlier, SC granted bail to Chidambaram
Chidambaram, who was also the Home Minister in the UPA era, spent some weeks in Tihar jail before being granted bail by Supreme Court earlier this month, in the case registered by CBI.
Rejecting the premiere agency's arguments, SC said there was no whisper of evidence that the politician tried to influence witnesses.
He is also not a flight risk, the top court noted.
SC considered his age while taking the decision
"The appellant Chidambaram is said to be aged 74 years and is also said to be suffering from age-related health problems. Considering the above factors and the facts and circumstances of the case, we are of the view that the appellant is entitled to be granted bail," SC said.
Separately, ED took care of some of Chidambaram's demands
To Chidambaram's misfortune, the bail didn't translate to freedom, as by the time the order came he had been shifted out to Tihar to ED's custody.
The agency had promised the politician would get home-cooked food, a western toilet, medicines, and a separate cell.
However, the agency had strongly opposed his demand for an air-conditioner but said his family can visit him.
Taking potshot at BJP, he said people have regained control
Meanwhile, Chidambaram's jibes at the current regime haven't stopped even from inside the prison.
Last week, after the results of Maharashtra and Haryana polls brought bad news for BJP, he tweeted, "The BJP government was determined to take control over the people and institutions. The election results have shown that people have begun to regain control."
Now, institutions should assert their independence, he added.