British prosecutors have authorised 38 further charges against Andrew and Tristan Tate, substantially expanding the criminal case that the United Kingdom is seeking to pursue while the brothers challenge extradition from the United States.

The new charges relate to four additional alleged victims and bring the total number of alleged victims in the British case to seven.

They were announced after prosecutors received a further file of evidence from Bedfordshire Police.

The alleged offences are said to have taken place between July 2010 and August 2017.

Andrew Tate, 39, faces seven additional counts of rape, three counts of arranging or facilitating trafficking for sexual exploitation, three counts of assault occasioning actual bodily harm, and 19 further charges relating to indecent images of a child and extreme pornography.

Tristan Tate, 38, faces one additional count of sexual assault, two counts of rape and three counts of arranging or facilitating trafficking for sexual exploitation.

The brothers were already facing 21 UK charges linked to three alleged victims.

Those earlier allegations include rape, assault occasioning actual bodily harm, human trafficking and, in Andrew Tate's case, controlling prostitution for gain.

Taken together, the existing and newly authorised counts amount to 59 charges.

The charging decisions are not findings of guilt.

Prosecutors decide whether there is sufficient evidence and a public-interest basis to bring a case before a court; guilt or innocence can only be determined through a criminal trial.

Both brothers deny the allegations and say they will fight extradition.

The additional charges came to public attention after court documents connected to the American extradition proceedings were unsealed.

The filings set out prosecutors' allegations in greater detail and were used in arguments over whether the brothers should remain in custody while the United States considers the British request.

The documents contain serious allegations of rape, sexual assault, trafficking for sexual exploitation and physical violence.

Those allegations remain unproven, and the identities of complainants are protected.

Criminal proceedings are active, making it important that public commentary does not identify alleged victims or prejudice any future trial.

The Tate brothers were arrested by the US Marshals Service on 18 July after British prosecutors sought their extradition in relation to both the original and the additional charges.

Their legal team has argued that they are not a flight risk and has said the allegations are meritless.

The brothers' lawyer has stated that they intend to contest the extradition request.

The UK case is separate from criminal proceedings involving the brothers in Romania, where they have also denied allegations of rape, human trafficking and forming an organised criminal group.

Romanian proceedings have complicated the question of where the brothers would face trial first.

A Romanian court previously ordered their extradition to the United Kingdom after the conclusion of the Romanian criminal process.

The brothers have long been high-profile online figures, with millions of followers and a history of controversy over their public statements about women.

Their reach has also shaped the legal handling of the case.

British prosecutors have argued that complainants require protection from possible identification or interference through social media.

In June, the High Court in London rejected an attempt by the brothers to force prosecutors to disclose the names of complainants before extradition.

The court accepted that prosecutors could withhold the identities at that stage because of the need to protect witnesses and the integrity of future proceedings.

It said the brothers would receive the information after extradition and before their first court appearance in Britain.

The distinction between the criminal allegations and separate civil claims is also significant.

Four women have brought a civil action in England against the brothers, but those claimants are not the alleged victims in the newly expanded British criminal prosecution.

The civil case and the criminal proceedings have different legal tests, evidence rules and timetables.

The expanded charges increase the stakes of the extradition case, but they do not resolve it.

American courts must determine whether the legal requirements for extradition are met, while the brothers retain the right to challenge the request.

If extradited, they would face proceedings in the United Kingdom on the charges authorised by the Crown Prosecution Service.

The next immediate stage is the US extradition process, which will decide whether Andrew and Tristan Tate are transferred to British custody to answer the 59 UK charges in court.