But only the Congress activist, Srivatsa B - he heads the party's social media cell in Karnataka - will be questioned, according to the poll body's order setting up an inquiry into the alleged leak.
The Election Commission said that is because the BJP has already explained.
The order setting up the six-member committee had asked it to "enquire form Shrivatsa B...regarding the source of information of his tweets" on the Karnataka election schedule before its official announcement.
Mr Malviya's name was not even in the order, which has spurred critics to call the inquiry a "joke".
Later in the day, the Election Commission put out the responses that it had received from the three parties: Mr Malviya, Mr Srivatsa of the Congress and the television channel, Times Now.
Congress spokesperson Divya Spandana had earlier questioned why its order did not name the leader from the BJP, but only the Congress.
"Dear EC, while we welcome any investigation to ensure that your credibility is not undermined however find it extremely shocking that IT head of BJP has been absolved even before enquiry begins. This definitely dents your own image and authority," she tweeted.
Name of BJP IT cell chief Amit Malviya does not figure in EC inquiry order on how Karnataka election dates were leaked. EC order below has absolved him even before any probe & EC so-called inquiry is merely a joke : pic.twitter.com/caqCZz8kXGNagendar Sharma (@sharmanagendar) March 28, 2018
The Election Commission, however, said it didn't t need to question Mr Malviya at all, since he wrote to the poll body explaining the source of his tweet and the letter had been taken as his response. The top election body also said a BJP delegation had come and met its commissioners last evening with Mr Malviya's letter. "The delegation submitted all facts to the EC," said an official.
Mr Malviya had deleted within moments his tweet, which had the date of counting wrong (May 18 instead of 15).
Karnataka will vote on May 12 and the results will be declared on May 15.