Brewer, who previously led the Met’s anti-trafficking unit said it made sense to make Operation Cornpoppy a trafficking investigation, because it would expand the “investigative strategy”.

He said: “When you start looking wider, the emphasis isn’t on the survivor themselves in terms of their account alone, and it means that we’re not just looking at one person’s word against another, we then start hopefully identifying and seizing evidence that supports, corroborates the stories that they’ve provided.”

Separately, in a letter to the force, shared exclusively with the BBC, lawyers Leigh Day said: “We appreciate the Modern Slavery Act came into force in July 2015 and that the Act itself is not retrospective in relation to historic allegations. However, it does, crucially, provide investigators a prism or lens to look at patterns of behaviour that might otherwise be investigated as ‘historic sexual abuse’ or ‘sexual misconduct’.”

Leigh Day said the force’s approach was “limited”.

Al Fayed died in 2023 aged 94 having never faced charges. His brother Salah died in 2010 also having faced no charges.

Al Fayed owned Harrods between 1985 and 2010, with most of the abuse alleged to have happened during that time.

A spokesperson for the Metropolitan Police, said: “The live investigation into those who could have facilitated or enabled Mohamed Al Fayed’s offending continues.

“The way the Met works has moved on immeasurably, and our teams have transformed the way we investigate rape and sexual offences. We’re working with partners across the criminal justice system to ensure that victim-survivors are at the heart of our response, with a greater focus on suspects and their offending.

The Met has said that the live investigation into those who could have facilitated or enabled Al Fayed’s offending continues and urged anyone with information whether directly affected by Mohamed Al Fayed’s actions or those aware of others who may have been involved, or committed offences, to come forward.

Harrods has told the BBC the independent external investigation it had established into whether any current employees knew about the alleged abuse “is now concluding”.

It confirmed, in relation to action taken by Harrods, one employee left the business last year.