Twitter’s systems unfairly filtered 600,000 accounts including some belonging to members of US Congress, Chief Executive Jack Dorsey has admitted.
Mr Dorsey made the admission during a statement on Wednesday to the US House Energy and Commerce Committee, which is looking into the social network’s algorithms and content monitoring.
The Twitter boss said the company’s algorithms were to blame for hiding some members from its auto-complete search, but that they had since fixed the issue.
Mr Dorsey said: "In the spirit of accountability and transparency: recently we failed our intended impartiality.
"Our algorithms were unfairly filtering 600,000 accounts, including some members of Congress, from our search auto-complete and latest results. We fixed it. But how did it happen?"
‘We decided it wasn’t fair’
Mr Dorsey did not provide specific numbers about whether more Republican or Democrat Congress members were filtered out by the process.
He added: “Looking at the data, we analysed tweets sent by all members of the House and Senate, and found no statistically significant difference between the number of times a tweet by a Democrat is viewed versus a Republican, even after our ranking and filtering of tweets has been applied.
"Our technology was using a decision-making criteria that considers the behaviour of people following these accounts.
"We decided that wasn't fair, and corrected. We'll always improve our technology and algorithms to drive healthier usage, and measure the impartiality of outcomes."
This comes after several Republicans, including US President Donald Trump accusing Twitter of shadow-banning conservative voices - an act where someone’s visibility to the public is reduced.
Twitter has denied the claims.
President Trump previously said on Twitter: "Social media is totally discriminating against Republican/Conservative voices.
"Speaking loudly and clearly for the Trump administration, we won't let that happen.
"They are closing down the opinions of many people on the RIGHT, while at the same time doing nothing to others..."