Supreme Court revives controversial US data system for citizenship checks

The US Supreme Court has lifted restrictions on the Trump administration to use a controversial federal database that uses citizenship information and other sensitive data to identify voters suspected of being non-citizens.

Critics have questioned the reliability of the data, warning it could result in US citizens being wrongly removed from electoral rolls.

In June, a federal judge ruled that the system was illegal and violated the privacy rights of Americans.

But the top court's conservative majority ruled that the National Voter Registration Act prohibits broad purges of voter rolls in the weeks before an election, which limits any "potential impact" of the decision ahead of the midterms.

The three liberal-leaning liberals on the Supreme Court dissented from the decision.

One of the dissenting Supreme Court justices, Ketanji Brown Jackson, expressed concern that this could mistakenly revoke the voting rights of eligible voters.

"The harm caused by burdening or disenfranchising even a few lawful voters outweighs the non-existent harm that the government experiences when it is prevented from taking an action that it likely lacks the authority to take," she wrote.

The Department of Homeland Security programme, known as Systematic Alien Verification for Entitlements, or SAVE, allows officials to verify the eligibility of voters on their rolls.