As Twitter handed over to the US Senate the details of 201 handles linked to alleged Russian efforts to meddle in the presidential elections last year, a separate report has suggested that the micro-blogging website might have deleted data crucial to the probe.
The handover of the Twitter details took place this week, Xinhua quoted US media reports saying on Friday. It was part of the social networking service's effort to aid in the Russian probe.
Those handles were previously not submitted partly due to legal privacy issues.
The move has attracted criticism from the investigators looking into Moscow's suspected manipulation of the social media service during the 2016 election.
"The investigators also believe that their best hope for identifying who was behind these operations, how they collaborated with one another and their suspected links to the Kremlin lie buried within the data accumulated in recent years by Twitter," the report said.
By analysing Twitter data, the investigators could have established a "pattern of life behaviour", determining the Russian influence on the elections.
"But a substantial amount of valuable information held by Twitter is lost for good. The data was of potentially irreplaceable value to investigators," cybersecurity analysts and other current and former US officials, were quoted as saying.
Federal investigators now believe Twitter was one of Russia's most potent weapons in its efforts to promote Donald Trump over Hillary Clinton, the officials who spoke on condition of anonymity, were quoted as saying.
The officials said that by creating and deploying armies of automated bots, fake users, catchy hashtags and bogus ad campaigns, unidentified operatives launched recurring waves of pro-Trump and anti-Clinton story lines via Twitter that were either false or greatly exaggerated.
Facebook COO Sheryl Sandberg has said that Facebook owes American people an apology for the way it handled Russia's interference in last year's presidential election.
"It's not just that we apologize. We're angry, we're upset. But what we really owe the American people is determination" to do a better job of preventing foreign meddling, Sandberg told the Axios news website during an interview in Washington.
The Senate has invited Twitter, along with Facebook and Google, to a public hearing set for 1 November.