The law enforcement agency has also drafted in the government’s terrorism watchdog, Jonathan Hall QC, to lead its case against the pair in a further sign of its commitment to end the secrecy and seize their allegedly dirty money.

The new developments came at a hearing at Westminster Magistrates to prepare for forfeiture proceedings later this year at which the NCA will seek to take possession of around £6.5 million in ten bank accounts held by one or other of the couple.

The Evening Standard has been fighting for nearly two years to name the pair, who own several multi-million pound properties in London, after discovering that their savings, which include accounts at the Queen’s bank Coutts, had been frozen by law enforcers.

The NCA had remained officially neutral during a series of earlier hearings at which this newspaper’s applications to name the couple were blocked by court orders, despite a judge’s admission that the Standard has an “important story to tell, in the public interest” and “is concerned about the flow of dirty money into the UK”.

But the NCA has now changed its stance in a skeleton argument submitted to Westminster Magistrates by Mr Hall, one of the country’s leading QCs in “dirty money” cases and also the independent reviewer of terrorism legislation.

In it, Mr Hall calls for the removal of secrecy – which means the couple can only be referred to X and Y – arguing that the pair “have not come close to justifying the need for anonymity.”

“In contrast to its position of neutrality at earlier stages of the proceedings … the NCA now argues positively that the final hearing should be in open court and that there should be no restrictions on identification,” he states.

Mr Hall points out that “Mrs Y has been the director of a UK limited company, with publicly accessible records including financial statements” and that the couple have “also used limited companies in relation to their business affairs in Azerbaijan” and given their names and personal signatures on commercial documents.”

He adds that “Mrs Y also appears to have provided her name, passport number and personal UK bank details” on an invoice.

“This is not a case where there is any particular confidentiality that they have sought in relation to their business and financial affairs,” he concludes in the legal document.

Mr Hall also rejects earlier arguments by the couple’s lawyers that the forthcoming forfeiture hearing should be conducted in private.