Nicholas Rossi, 35, was due to appear in the dock at Edinburgh Sheriff Court as part of a long-running battle to extradite him over alleged sex offences, launched by authorities in the state of Utah.

His absence in court was explained by his solicitor, Stuart Murray, who told Sheriff Norman McFayden that there "appeared to be some difficulty downstairs".

Advocate Depute, Paul Harvey, said there had been an "altercation", while Mr Murray said the defendant denied refusing to come to court.

Rossi, who is accused of faking his own death to try to avoid US allegations, has claimed he is an Irish orphan named Arthur Knight, and not a US citizen.

But last November, after months of hearings, Sheriff McFayden ruled he was the man American authorities have been seeking in connection with rape and sexual assault charges.

Sheriff McFayden said it was his understanding that staff were not prepared to take Rossi to court following Thursday's alleged altercation.

Defence lawyers are still waiting for reports on Rossi's psychiatric and physical health.

They are also awaiting further reports on human rights in US prisons and facilities in Utah - to where Rossi would be flown to if the extradition request is successful.

Mr Harvey said prosecutors needed sufficient time to assess the reports, which had been instructed earlier this year.

He insisted the proposed date for the full extradition, on 26 June, "cannot change".

"I say all that against a background of delay, obstructionism, and denial about this requested person," Mr Harvey told the court.

"These proceedings, the obstructionism and denial, have gone on simply too long."

Sheriff McFayden said he would give the defence a further fortnight for expert reports to be acquired, setting a deadline for 4 May.

A further preliminary hearing has been scheduled for 22 May, with Rossi remanded in custody.

Defendant 'faked death to avoid prosecution'

He was alleged to have faked his own death three years ago and fled to the UK to dodge prosecution.

Rossi was arrested in October last year after checking himself into the Queen Elizabeth University Hospital in Glasgow with COVID-19.

While in Scotland, under the alias Knight and posing as a tutor, Rossi developed COVID pneumonitis and became "the sickest patient on the ward", according to medical staff who were caring for him at the time.

Police Scotland officers were then issued with an Interpol red notice, with pictures of the wanted man, including images of his tattoos and fingerprints.