The Gujarat ATS detained Teesta Setalvad from her Mumbai home.
Activist Teesta Setalvad was taken into custody by the Gujarat Police's Anti-Terrorism Squad from Mumbai on Saturday, a day after the Supreme Court lashed out at those who had "kept the pot boiling" on the 2002 Gujarat riots.
A complaint filed this morning by the Gujarat Police against her, seen by NDTV, cited the strongly-worded Supreme Court judgment that included allusions to Ms Setalvad's NGO which has worked extensively with the victims of the riots.
The activist has been accused of forgery and falsification of records among other charges in the complaint that also names former police officers RB Sreekumar and Sanjiv Bhatt, who too had accused the Gujarat government of preventing the police from stopping the riots.
Ms Setalvad was a co-petitioner in the case that was dismissed by the Supreme Court on Friday that challenged Prime Minister Narendra Modi's exoneration. Zakia Jafri, wife of Congress MP Ehsan Jafri who was killed in the riots, was the main petitioner.
Upholding the clearance to PM Modi, then Chief Minister of the Gujarat, by a court-appointed Special Investigation Team or SIT, the Supreme Court said the case was "devoid of merits" and was filed "obviously, for ulterior design".
"All those involved in such abuse of process need to be in the dock and proceeded with in accordance with law," the judges said, surmising that Ms Jafri's appeal was filed under "dictation of someone".
In the past, after PM Modi came to power at the centre, Ms Setalvad has had run-ins with the CBI and Gujarat Police, over allegations of financial misappropriation at her NGO.
Ms Setalvad's detention came hours after Union Home Minister Amit Shah, in an interview to news agency ANI, said that Ms Setalvad gave baseless information about the Gujarat riots and helped run a campaign to stain PM Modi's image.
"I have read the judgement very carefully. The judgement clearly mentions the name of Teesta Setalvad. The NGO that was being run by her - I don't remember the name of the NGO - had given baseless information about the riots to the police," Mr Shah said.
At a later point in the interview he said, "I have read the judgment hurriedly but it clearly states the name of Teesta Setalvad. It was Setalvad's NGO that gave an application involving BJP workers in every police station and the pressure by the media was so immense that every application was treated as truth."