New York, Aug 12 (IANS): Former Twitter CEO Dick Costolo had secretly ordered employees to filter out abusive and hateful replies to US President Barack Obama during the May 2015 #AskPOTUS town hall meeting, the media reported on Friday.

According to Buzzfeed, Costolo asked employees to deploy an algorithm which was built in-house to filter out abusive language directed at Obama.

"Another source said the media partnerships team also manually censored tweets, noting that Twitter's public quality-filtering algorithms were inconsistent," the report added.

The decision was kept secret from senior employees who followed Twitter as long-standing commitment to free speech.

After a month Obama's town hall meeting, Costolo stepped down as CEO.

In an exit interview with The Guardian, he defended Twitter's commitment to free speech, saying that "I will say directly that I think regulation is a threat to free speech".

In its early years, Twitter took several stands against censorship, even in the WikiLeaks case.