Amanda Knox not guilty
Amanda Knox talks to the press surrounded by family outside her mother's home in Seattle Reuters

US President Donald Trump was reportedly "very upset" his 2016 election campaign did not have the backing of Amanda Knox.

The president had previously tweeted about Knox, who was convicted of the murder of her flatmate Meredith Kercher in Perugia, Italy in 2007 before being found not guilty during a retrial in 2011.

During Knox's well-publicised trial, Trump was one of her most vocal supporters, tweeting in 2011 prior to her acquittal: "Everyone should boycott Italy if Amanda Knox is not freed – she is totally innocent."

However, one of Trump's friends, George Guido Lombardi, told the New York Times on Friday (14 April) that the president was disappointed Knox backed Democrat Hilary Clinton in the 2016 US presidential election.

In a post on her blog, Knox, who was definitively acquitted by the Supreme Court of Cassation in 2015, wrote of Trump: "Donald Trump has succeeded in coming a step away from the most powerful position in the world merely because he is a destabilising agent. No matter that he is inexperienced, uninformed, and irresponsible (to say the very least)."

Her decision to back Clinton for president reportedly left Trump disappointed, according to Lombardi. He told the New York Times the president was "very upset" with Knox's "ingratitude".

Knox has not commented on Lombardi's claims although she has not hidden away from the media circus that surrounded her trial, conviction and eventual acquittal. In 2016, she appeared in a Netflix documentary in which she told the story of her incarceration and release.