Weiss is expected to push back against comments by two whistleblowers from the Internal Revenue Service tax agency, who say he told officials at a meeting that he did not have final authority to decide to bring charges as part of his probe.
“Mr Weiss is prepared to take this unprecedented step of testifying before the conclusion of his investigation to make clear that he’s had and continues to have full authority over his investigation and to bring charges in any jurisdiction,” a spokesman for Weiss said ahead of his appearance.
House Republicans allege that the justice department improperly interfered with an investigation into Hunter Biden, whose brushes with the law are a central focus of their impeachment enquiry into President Biden.
The White House has denied wrongdoing. Democrats say the impeachment enquiry is politically motivated.
In keeping with justice department policy, Weiss will not address specifics in his probe, the spokesman said.
Like all special counsels, Weiss will produce a report when his investigation is completed. It is not clear when that will take place.
At least nine current and former officials from the Federal Bureau of Investigation, IRS and justice department have testified behind closed doors as part of lawmakers’ probe.
Weiss has headed an investigation into Hunter Biden since 2019. Originally nominated during Republican President Donald Trump’s administration, he was allowed to remain in place under Biden.
Weiss has charged Hunter Biden, 53, with crimes related to owning a firearm while using illegal drugs. The president’s son has said he struggled with addictions to alcohol and crack cocaine. Those charges came after a plea deal over misdemeanour criminal tax and gun charges collapsed.
The impeachment enquiry has been cheered on by Trump, who is the leading candidate for the Republican presidential nomination to take on Biden again in the 2024 election. Trump was also the first US president to be impeached twice. The Senate acquitted him both times.
Trump is facing four criminal indictments for charges related to his business activities, mishandling of classified documents, and attempt to overturn the 2020 election.
It is not clear if the full House of Representatives, controlled by a narrow 221-212 Republican majority, would support impeaching Biden.