US President Donald Trump claimed on Monday that pardons made by former President Joe Biden were “void, vacant and of no further force and effect” as he claimed that those pardons were signed by an “autopen”.

In a post on Truth Social, Trump said that his predecessor Biden’s pardons for members of the House select committee that investigated the January 6, 2021 attack on the US Capitol are invalid as “Joe Biden didn’t sign them”.

“The ‘Pardons’ that Sleepy Joe Biden gave to the Unselect Committee of Political Thugs, and many others, are hereby declared VOID, VACANT, AND OF NO FURTHER FORCE OR EFFECT, because of the fact that they were done by Autopen,” Trump wrote in the post.

Trump added that “Joe Biden did not sign them but, more importantly, he did not know anything about them.” The Republican president claimed that all committee members would be “subject to investigation at the highest level”.

However, the US Constitution states that the president has executive powers to issue pardons but makes no mention about subsequent presidents revoking the pardons.

According to the US Department of Justice website, “The President need not personally perform the physical act of affixing his signature to a bill he approves and decides to sign in order for the bill to become law.”

Former President Joe Biden had pardoned his son Hunter Biden, who was facing sentencing for two criminal cases. Hunter had pleaded guilty to tax charges in September last year, and was found guilty of being an illegal drug user in possession of a gun in June.

Hunter Biden became the first child of the sitting president to have been convicted of the crime. Joe Biden had earlier rejected the idea of pardoning him but later issued the pardons.