On Sunday, the Republican congresswoman tweeted a clip of the former news anchor telling Fox News his family had received threats for reporting on former US president Bill Clinton and his wife Hillary Clinton in footage from 2019.
Although the Hoover Police Department confirmed that his death was being investigated as a suicide on Saturday, Ms Boebert referred to an anti-Clinton conspiracy as a cause of the 45-year-old’s death.
She wrote : “Why is it that so many who cross the Clinton Crime Syndicate end up dead?”
Mr Sign, who was found dead at home in Hoover, Alabama, told Fox News in a 2019 interview that he had been threatened following his 2016 story on Ms Clinton, the former US secretary of state.
As Newsweek reported, Mr Sign was the first to report on a meeting between Mr Clinton and then-attorney general Loretta Lynch during an investigation into Ms Clinton’s use of a private email sever as secretary of state.
"My family received significant death threats shortly after breaking this story,” he said in the Fox News interview. “That's why I came back to WBMA ABC 33/40 in Birmingham [from KNXV-TV in Phoenix].”
Ms Clinton’s emails became a focus for former US president Donald Trump, who defeated the 2016 Democratic nominee on the back of nicknames including “Crooked Hillary”.
It is not the first time Ms Boebert has alluded to a conspiracy in the style of QAnon, which theorises that Democrats and a world elite are running a sex trafficking ring — with its so called members, including Ms Clinton, supposedly facing arrest or a day of reckoning.
The congresswoman, asked in February if Democrats and Ms Clinton will be arrested, allegedly told the Delta County Independent; “I believe we will see resignations begin to take place”.
Ms Clinton herself recently said of the false theories: "It's hurtful. I'll be really honest with you. It's hurtful not just to me and my family, but to my friends and other people to know that this is not just false, but sometimes painfully false."