Speaking to reporters, Karti Chidambaram said the alleged act happened in 2008 and there is no charge sheet till now.
He recalled that the Central Bureau of Investigation (CBI) had summoned him several times and each time had spent about 10 hours at the investigating office answering questions.
His father too appeared before the investigating agencies earlier, he added.
"But there is no charge sheet till date, which means there is no case at all," Karti Chidambaram said, adding that the arrest had been made "to satisfy someone in the government".
He also claimed that the arrest was to divert the nation's attention from other serious issues and denied his father was "absconding" since Tuesday night after the Delhi High Court rejected his anticipatory bail plea and the Supreme Court declined him any interim relief.
In a series of tweets earlier, Karti Chidambaram thanked the Congress party for its support to his father and termed the "drama and spectacle" being enacted by the probe agencies was for the "voyeuristic pleasure of some".
"The drama and spectacle being enacted by the agencies is to simply sensationalise and satisfy the voyeuristic pleasure of some," he tweeted as CBI and ED officials scaled the boundary wall of the Jor Bagh residence of his father to arrest him.
"I am thankful to the @INCIndia Shri @RahulGandhi, @priyankagandhi, for their support. And ever grateful to @KapilSibal, @DrAMSinghvi, @salman7khurshid, for being there with us throughout."
"I have been raided 4 times. Appeared for over 20 summons. Each session for a minimum of 10 to 12 hours. Been a 'guest' of the CBI:) for 12 days. There is still no chargesheet for alleged events which apparently took place in 2008 and a FIR in 2017. There is no case."
( With inputs from IANS )