The US Justice Department will launch a grand jury investigation into allegations that senior officials in former president Barack Obama’s administration manipulated intelligence on Russian interference in the 2016 election, a source familiar with the matter said.

US Attorney General Pam Bondi has reportedly directed federal prosecutors to move forward with legal proceedings, based on claims made by Director of National Intelligence Tulsi Gabbard, who has alleged the "weaponisation of the US intelligence community."

A DOJ spokesperson declined to comment.

Fox News first reported that Bondi personally instructed an unnamed prosecutor to present Justice Department evidence to a grand jury.

If prosecutors pursue a criminal case, the jury could consider indictments.

The investigation stems from accusations by Republican President Donald Trump, who has seized on Gabbard’s remarks. Gabbard, a former congresswoman, claimed recently declassified documents show what she called a "treasonous conspiracy" to undermine Trump’s campaign in 2016 — charges Democrats have rejected as baseless and politically driven.

Trump last month accused Obama of treason, alleging that he directed efforts to tie Trump to Russia and damage his candidacy. Trump defeated Democrat Hillary Clinton in the 2016 election.

A spokesperson for Obama dismissed the claims as "ridiculous and a weak attempt at distraction."

The original 2017 assessment by the US intelligence community concluded that Russia tried to influence the election in Trump’s favour through hacking, online disinformation, and social media bot networks. However, the report found no evidence that Moscow’s efforts changed vote outcomes.

Russia has consistently denied interfering in any US election.