It should not be “rocket science” to prove the identity of an alleged fugitive facing extradition to the US over sex charges, a sheriff has said.

Sheriff Kenneth Maciver told Edinburgh Sheriff Court it is “pressing” to establish the identity of the man alleged to be Nicholas Rossi, who is said to have faked his own death to escape charges in the US.

Prosecutors there say the man is Rossi, who allegedly raped a 21-year-old in Utah in 2008 and is also alleged to have attacked women elsewhere in the United States.

However, the 35-year-old man claims to be called Arthur Knight, a victim of mistaken identity who has never been to America.

Sheriff Maciver told the man’s defence agent Ronnie Renucci KC that the issue of identity will be the first question the court has to answer at the extradition hearing.

He said: “The court has to be satisfied that the person is the person sought by the United States.

“It is a serious matter if the person here is not the person sought by the United States, which I understand is his position.

“That is a matter that has to be resolved quickly now. That has been causing problems from day one.

“There are photos sent to the court in relation to identification, there are issues of DNA, fingerprints, there are also physical issues, facial photos which can be shown to facial experts, there are body photos with tattoos.

“He could for example submit photos showing he has no tattoos on either arm, these are important issues which would allow us to move on with identification.”

Fiscal depute Clare Kennedy confirmed the Crown now has fingerprints.

The 35-year-old man, who appeared by video-link from HMP Edinburgh on Thursday wearing an oxygen mask, denies he is the alleged fugitive.

When asked by Sheriff Maciver whether he is Rossi, he replied: “No, good morning your Lordship, I am Arthur Knight and I would ask your Lordship if we could begin with a moment of silence in memory of her great Majesty.”

Sheriff Maciver said the issue of identity is not that difficult and can be tested in cross-examination and through the production of information such as photos, birth and marriage certificates and testimonials from friends.

He added: “It’s not rocket science.”

Mr Renucci said the issue of identity is a priority.

He said: “I’m aware that the issue of identity is absolutely critical and crucial. I understand steps will be taken to try and iron that out.”

The court also heard that a doctor is preparing a psychological report for the defence but there have been some difficulties in obtaining medical records because they are in the name of Rossi, while the man claims to be Mr Knight.

However it is hoped that the issue can soon be resolved.

A further hearing will take place on October 6 and the full extradition hearing is likely to take place in early November.