A missing Maltese professor who promised the Trump campaign “dirt” on Hillary Clinton in the run-up to the presidential election may be dead, a US court has been told.

Joseph Mifsud, a former teaching fellow at Stirling University, held meetings in 2016 with George Papadopoulos, a former Trump administration foreign policy adviser who was jailed last week for lying to the FBI, including over his connections to the 57-year-old professor.

Prosecutors in the Papadopoulos case allege Mr Mifsud touted his “substantial connections with Russian government officials”, who could deliver “thousands of emails” featuring incriminating information against Ms Clinton.

But in unrelated court filings last week, the Democratic National Committee (DNC) claimed Mr Mifsud, who has not been seen since November last year, "may be deceased".

The DNC is suing Russia, WikiLeaks and the Trump campaign over alleged interference in the 2016 election. Lawyers for the committee said it believed all defendants in the case were served with complaints, “with the exception of Mifsud (who is missing and may be deceased),” according to Bloomberg. They did not elaborate.

Court documents relating to the Papadopoulos case revealed the young foreign policy adviser initially tried to downplay Mr Mifsud as “a nothing” and “just a guy talk[ing] up connections or something”.

“In truth and in fact, however, defendant Papadopoulos understood that the professor had substantial connections to Russian government officials (and had met with some of those officials in Moscow immediately prior to telling defendant Papadopoulos about the ‘thousands of emails’),” the statement of offence read.

Mr Mifsud went missing last year, shortly after special counsel Robert Mueller announced the first charges relating to his investigation into links between Russia and the Trump administration.

On 30 October, Mr Mueller’s office made public Papadopoulos' guilty plea, as well as charges against former Trump campaign manager Paul Manafort and his associate Rick Gates.

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On 1 November, La Repubblica located Mr Mifsud in Rome. The academic told the newspaper he met Papadopoulos “three of four times”, but that the claims over election interference were “nonsense”.

“Papadopoulos doesn’t tell the truth,” he said. “The only thing I did was to facilitate contacts between official and unofficial sources to resolve a crisis. It is usual business everywhere. I put think tanks in contact, groups of experts with other groups of experts.”

He continued: “I strongly deny any discussion of mine about secrets concerning Hillary Clinton. I swear it on my daughter. I don’t know anyone belonging to the Russian government.”

Mr Mifsud appears not to have been seen since he made those comments, even by Italian prosecutors attempting to track him down over an unrelated court summons in Italy.

His Ukrainian fiancée, who reportedly gave birth to his daughter earlier this year, has also said she has not seen him in months.

As well as offering emails, Mr Mifsud also introduced 31-year-old Papadopoulos to a woman named Olga, who claimed to be a niece of Russian president Vladimir Putin, and a man named Ivan Timofeev, who claimed to have a connection to the Russian Ministry of Foreign Affairs.

Prosecutors said Papadopoulos’s false statements to the FBI contributed to their inability to secure an interview with the professor.

“The defendant’s lies undermined investigators’ ability to challenge the professor or potentially detain or arrest him while he was still in the United States,” they wrote in court papers, noting Mr Mifsud left the US in February 2017 and has not returned.

Papadopoulos was sentenced to 14 days in prison. Prosecutors had asked for a sentence of six months. They said Papadopoulos thwarted a national security investigation with his false statements.

A hearing into the DNC lawsuit is set for 13 September.