WASHINGTON (Reuters) -U.S. prosecutors said in a court filing on Wednesday they will seek an indictment of President Joe Biden's son, Hunter, by Sept. 29 in his tax and firearms case.

Hunter Biden has said in court filings that prosecutors reneged on a plea deal that would have resolved the charges.

In July, U.S. District Judge Maryellen Noreika rejected a proposed plea deal, raising concerns over its legality and the scope of immunity it offered Hunter Biden.

Under that proposed arrangement, Hunter Biden would have pleaded guilty to not paying taxes on $1.5 million in income between 2017 and 2018 and entered into a separate deferred prosecution agreement for illegally owning a firearm while using drugs, a felony.

(Reporting by Kanishka Singh and Eric Beech; editing by Rami Ayyub and David Gregorio)