The Royal household will not be exempt from scrutiny over pedophile allegations and may be asked to provide evidence to a newly launched child sex abuse inquiry, it has emerged.

Justice Lowell Goddard, the New Zealand judge chairing the Independent Inquiry into Child Sexual Abuse, had initially not included the Royal household in a list of institutions to be investigated over historical crimes.

However, a statement from the inquiry, launched on Thursday, later confirmed the monarchy would also be “within the scope” of the investigation.

The child abuse inquiry could take up to five years and cost £100 million, it has been confirmed, as authorities will investigate every level of British society including local authorities, the police, the Crown Prosecution Service (CPS), the NHS, the media and armed forces.

Justice Goddard told the Times: “There is no limit on the types of institutions that fall within the terms of reference. The monarchy is an institution and it runs a number of other institutions, all of which are potentially within the scope of the inquiry.”

READ MORE: ‘High-level corruption’: Investigations into police ‘cover-up’ of child abuse expanded

In a statement, Goddard described the investigation as “the most ambitious public inquiry” ever undertaken in England and Wales.

The Royal household has come under scrutiny in recent years following several allegations of child sexual abuse.

The Duke of York (Prince Andrew) came under the media spotlight in January after being accused of having forced sexual relations with an American teenager who was underage at the time.

He was named in court papers relating to an ongoing civil case by Virginia Roberts, 30, against convicted billionaire pedophile Jeffrey Epstein in the United States.

US judge Kenneth Marra ruled the sex allegations against Prince Andrew be struck from the public record in April, but made no ruling as to whether the claims were true or false.

In March, a former police officer claimed a member of the British royal family was part of a pedophile ring under investigation by police until the case was suddenly dropped.

The former Metropolitan Police officer said the investigation, which took place in the late 1980s, was halted for national security reasons.

READ MORE: British royal pedophile allegations dropped in police cover-up, ex-cop claims

Speaking to the Sunday Mirror, the former officer said: “I was in a car with two other vice squad officers."

"They were discussing a madam who had provided a girl of about 15 to Oliver Reed ... the detective sergeant said he had just had a major child abuse investigation shut down by the CPS [Crown Prosecution Service] regarding a royal and an MP ... he did not mention names, but he said the CPS had said it was not in the public’s interest because it ‘could destabilize national security.’”

“What I was told has stayed with me to this day,” he added.

Goddard’s child abuse inquiry was set up last year following claims investigations into a pedophile ring that operated in Westminster in the 1980s were covered up.

Several government figures who were prominent in the 1980s have since faced allegations of sexual impropriety.

The late former home secretary Leon Brittan faced accusations of child sexual abuse shortly before to his death in January.

The CPS formally apologized for failing to investigate allegations of child sex abuse made against the late Liberal MP Cyril Smith, who was exposed as a pedophile following this death in 2010.