The Duke of York is considered a “person of interest” in the US investigation into disgraced late financier Jeffrey Epstein and Ghislaine Maxwell, it has been claimed.

An unnamed source, said to be close to the inquiry, told the Reuters news agency that investigators viewed Prince Andrew as a “person of interest” over his friendship with Epstein as part of their investigation into possible co-conspirators.

Representatives from the duke’s legal team have declined to comment.

Investigators have previously said they wished to speak to Andrew as a potential witness.

The lawyer Mark Stephens said the use of the phrase “person of interest” could be interpreted as a “ratcheting up of the pressure to try and heap public opprobrium on him to the level where he has to give an account of what it is that actually occurred”.

Last week Virginia Roberts Giuffre, who has alleged she was abused by Epstein, filed a civil complaint against Andrew in Manhattan federal court. Giuffre alleges Andrew forced her to have unwanted sex at Maxwell’s London home, and in the US, on three occasions when she was aged 17. Andrew has denied the allegations.

The phrase “person of interest” is a term used by law enforcement for someone who has not been arrested or formally accused of any crime. It has no legal meaning, but it is understood it can refer to someone who may have information that would assist the investigation, including as a potential witness.

Prosecutors investigating sex trafficking allegations against Epstein and his associates have previously sought Andrew’s cooperation, and accused him of repeatedly stonewalling and declining requests to schedule any interview with federal authorities.

The prince’s lawyers have rejected this, stating in June last year: “The Duke of York has on at least three occasions this year offered his assistance as a witness to the US Department of Justice.” They added then that the DoJ had “advised us that the duke is not and has never been a ‘target’ of their criminal investigations into Epstein” and that they had instead sought his confidential, voluntary cooperation.

While Andrew remains a person of interest to prosecutors in the office of the US attorney for the southern district of New York, they do not expect to be able to interview him in the foreseeable future, if ever, according to the source, Reuters reported. “He doesn’t seem to want to talk to us,” said the source.

Stephens, of the law firm Howard Kennedy, and one of the legal specialists advising the parents of Harry Dunn, who was killed when a car crashed into his motorbike outside a US military base in Northamptonshire, said the phrase “person of interest” appeared to be an escalation of pressure on the duke.

“Normally you would say ‘we believe he has information which would assist our inquiries’, or ‘assisting the law enforcement with their inquiries’, or ‘we only see him as a witness but he has important evidence to give’. All of these are formulations and phrases which are restricted to someone in the capacity of a witness,” said Stephens.

“In my judgment, lexicon, a person of interest is different. That is saying we believe that there may have been some wrongdoing but we don’t know. And so our minds are still open but we need to speak to him in order to either include or eliminate him from our investigations.”

He added: “What they are trying to do, both in the civil and the criminal case, is to pile on reputational pressure so that it becomes impossible, reputationally, for him.”

Epstein took his own life in 2019 while awaiting trial on charges of trafficking minors. Maxwell has pleaded not guilty to charges that she procured teenage girls for Epstein to sexually abuse between 1994 and 2004. She is expected to go on trial in November.

Prosecutors last year sent the British government a formal request, known as a mutual legal assistance treaty submission, asking for access to the duke so they could talk to him.