A member of Congress has formally called on Sarah Ferguson to testify regarding her alleged "close personal and business ties" to Jeffrey Epstein, according to a letter obtained by the BBC.

Congressman Suhas Subramanyam requested that Ferguson provide information to a US congressional committee examining the activities of the late convicted sex offender. The lawmaker also asked her to share any knowledge related to her former husband, Andrew Mountbatten-Windsor, and his possible involvement in Epstein’s network.

The request marks the most significant effort yet to secure testimony from the former Duchess of York since the Epstein scandal began.

Representatives for Ferguson have been contacted for comment. Mountbatten-Windsor has consistently denied any wrongdoing connected to Epstein.

He has not responded to BBC inquiries concerning specific claims tied to the release of millions of Epstein-related documents in January.

Over the weekend, the BBC reported that several US lawmakers were seeking Ferguson’s testimony about her connections to Epstein.

There is currently no legal avenue available to force her to appear before a US committee.

The letter, sent Thursday with a two-week deadline for a reply, was authored by Subramanyam, a Democrat serving on the House Oversight Committee. It states that recently released files from the US Department of Justice point to Ferguson’s "close personal and business ties" with Epstein.

"As the committee seeks justice for the survivors of Mr Epstein's criminal enterprise, and transparency for the American public, I respectfully request your co-operation with the committee's investigation," he wrote.

The correspondence cites an email from a "Sarah" referring to Epstein as "a legend" after his 2008 conviction for soliciting prostitution from a minor, which included the line: "I am at your service. Just marry me."

It also points to messages indicating Ferguson sought financial support from Epstein.

"Additionally, while you officially divorced former Prince Andrew in 1996, the committee is interested in learning more about any knowledge of Mr Mountbatten-Windsor's involvement in Mr Epstein's operations," the letter said.

"It is clear that you possessed social and business ties to Mr Epstein and have knowledge of information that can assist our investigation," it went on.

"I request that you cooperate with the committee's investigation and provide information regarding the crimes of Jeffrey Epstein and his co-conspirators.

"Due to the urgency of this matter, I ask that you provide a response no later than April 9, 2026."

Documents released earlier this year by the US Department of Justice revealed additional details about Ferguson’s relationship with Epstein.

Being mentioned in the files does not in itself imply wrongdoing.

However, the scale of the document release suggested a deeper connection to Epstein’s circle than previously understood.

The records portray Ferguson as seeking financial assistance and emotional support, at one point reportedly describing herself to Epstein as "very traumatised and alone".

In a 2009 message, she is shown praising Epstein as "the brother I have always wished for".

Emails further indicate that she remained in contact with Epstein during his imprisonment for soliciting prostitution from a minor and that she brought her daughters to meet him for lunch in Miami shortly after his release.

Speaking to the BBC last weekend, Subramanyam said he believed Ferguson holds "information related to the investigation" and should testify before the committee.

Democratic Congresswoman Melanie Stansbury echoed that position, urging individuals with knowledge of Epstein’s activities to come forward in pursuit of justice for victims.

The committee, currently led by Republicans, has not signaled whether it will back efforts to formally request Ferguson’s testimony.

Relatives of Virginia Giuffre, a prominent Epstein accuser, have also called for Ferguson to cooperate with US authorities.

"If Ferguson knows anything, she should testify in the United States immediately," a representative for Giuffre's brother Sky Roberts told the BBC.

Lawmakers have repeatedly attempted, without success, to have Mountbatten-Windsor answer questions regarding his ties to Epstein.

Ferguson has already faced consequences stemming from her association with Epstein, including being dropped by several charities.

In October, she lost her duchess title after her former husband relinquished his Duke of York title amid scrutiny over his own links to Epstein. She also vacated Royal Lodge in Windsor, where the former couple had continued living together despite their 1996 divorce.