The action came almost a month after the CBI registered a case against Mumbai-based NGO Lawyers Collective and its President Anand Grover for alleged violation of the Foreign Contribution (Regulations) Act (FCRA), criminal conspiracy and criminal breach of trust.
The CBI searches, which started around 5 a.m. in both cities, followed a Home Ministry report.
Indira Jaising is not named in the CBI FIR. According to the CBI, unknown officer-bearers and functionaries of the NGO, private persons and public servants have also been made accused in the FIR.
The CBI officials said the searches took place at the residence and office of Jaising in Nizamuddin East in Delhi.
The Home Ministry report said the NGO was registered for carrying out social activities and it received Rs 32.39 crore from 2006-07 to 2014-15.
The violation of the FCRA was noticed in 2010, the complaint said.
The CBI case says Jaising got a remuneration of Rs 96.60 lakh from Lawyers Collective to travel abroad.
Delhi Chief Minister Arvind Kejriwal condemned the CBI raids, saying subjecting veterans who have fought for upholding the rule of law and constitutional values was a case of "clear vendetta".
"Let the law take its own course but subjecting veterans who have all through their lives fought for upholding the rule of law and constitutional values is clear vendetta," Kejriwal tweeted.
( With inputs from IANS )