Last weekend, Congressman Subramanyam told the BBC he now believed she had “information related to the investigation” and should give testimony to the committee.
His calls were echoed by Democratic Congresswoman Melanie Stansbury, who urged anyone with information of wrongdoing by Epstein and his associates to co-operate in order to ensure justice for the survivors.
The committee is controlled by Republicans, who have not indicated they would support the move to urge Ferguson to testify.
But the family of prominent Epstein accuser Virginia Giuffre also said they “strongly believed” the former Duchess of York should go to the US to answer questions.
“If Ferguson knows anything, she should testify in the United States immediately,” a representative for Giuffre’s brother Sky Roberts told the BBC.
US lawmakers have also repeatedly – and unsuccessfully – called for Mountbatten-Windsor to answer questions about his links to the late American financier and sex offender.
Ferguson has already been dropped by multiple charities over her Epstein links.
In October, she lost her duchess title when her ex-husband relinquished his Duke of York title over his links with Epstein, and she was also forced to move out of his Windsor mansion, Royal Lodge, where the couple lived together, despite having divorced in 1996.
On Thursday, she had her honorary Freedom of the City of York stripped, in a further fall from grace.
The city’s councillors voted unanimously to remove the honour from Ferguson, which she was given in 1987 after her marriage to the then-Prince Andrew, at an extraordinary meeting on Thursday evening.