A total of 111 women have accused Mohamed Al Fayed of abuse, with the youngest victim being just 13. Police are investigating more than five people for allegedly facilitating the late Harrods boss' offence.
Police have revealed that a further 90 alleged victims have made allegations against the billionaire, who died last year aged 94, bringing the total number of complainants to 111.
The allegations range from sexual assault to rape and span a period of 37 years, from 1977 to 2014.
A Harrods-appointed lawyer for the victims said the extent of the abuse could be on a similar scale to that suffered by Jimmy Savile.
The Metropolitan Police confirmed that more than 150 people have contacted them after launching a renewed appeal for information following a BBC expose about the businessman, whose son Dodi died in a car crash with Princess Diana.
The Complex Investigation Team (CIT), a special unit within the Met, has also launched an investigation into a number of individuals linked to Fayed. Detectives are trying to determine what role these individuals may have played in assisting and facilitating Fayed's offending.
The force is also reviewing all its previous investigations to identify missed opportunities to stop the deceased businessman. The results of the internal review will be published next month.
At least 21 women contacted the Met before his death with separate allegations of abuse, but he was never charged or tried after the Crown Prosecution Service twice refused to press charges.
The Independent Office for Police Conduct is reviewing complaints from two women about the Met's handling of investigations into their 2008 complaints against the Egyptian tycoon.
Although he was never criminally charged, dozens of women have filed legal claims against Harrods for alleged assault. The Knightsbridge retailer launched an internal investigation last year to see if anyone involved in any allegations is still employed, but it is not known when this will be completed.
The Met insists that previous investigations into the businessman were “extensive and carried out by specialist teams who twice requested charging decisions from the CPS”.
However, the force has acknowledged that “contact with and support for some victims at the time could have been improved”.
“While these cases are more than a decade old and we cannot change what happened in the past, we are committed to understanding, being open about any shortcomings and improving our response to survivors in the future,” the force said in a statement on Wednesday.
Commander Stephen Clayman of the Met's Specialist Crime Command added: “I recognize the bravery of every victim-survivor who has come forward to share their experiences, often after years of silence.
“This investigation is about giving survivors a voice, despite the fact that Mohamed al-Fayed is no longer alive and faces persecution. However, we are now prosecuting all those suspected of complicity in his offending, and we are determined to seek justice.
“We are aware that past events may have had an impact on public confidence in our approach, and we are committed to rebuilding that confidence by addressing these allegations with integrity and thoroughness.”
In a statement to journalists, Mr Clayman said the investigation would look at what role individuals “may have played in facilitating or enabling his offending, and what opportunities they had to protect victims from his horrific abuse.”
Dame Jasvinder Sanghera was appointed by Harrods as an independent advocate to meet the needs of the late billionaire's victims.
Dame Jasvinder told the BBC she saw evidence that Fayed's “tentacles went far and wide” as she discussed the extent of the abuse.
“We could be talking about something on the scale of Jimmy Savile,” she said.
After Saville's death in 2011, hundreds of survivors came forward with stories of abuse at the hands of the DJ and TV presenter, who used his work at the BBC and at hospitals, prisons and charities to cover up his wrongdoing.
And Dame Jasvinder believes Fayed's abuse went beyond the department store.
She said: “When you look at the scale of the abuse, it didn't just happen in Harrods. I'm already hearing from survivors that this has happened in other areas.”
She said a former student at a school for deaf children told her that Fayed “had access to vulnerable young women from that school.”
She said: “What we do know is that there are many people – and survivors have already said this to me – who were complicit [in Fayed’s abuse].
“They looked the other way. This could not have happened without people knowing about it, and he used his position of power and influence.”
The school told the BBC that, to its knowledge, Fayed did not have access to the facility and that it takes security very seriously.