It took more than a year for a formal inquiry to be launched into claims of a “toxic culture” in the Red Arrows that saw women plied with alcohol, treated like property and harassed for sex, a whistleblower has claimed.

Four former members of the squadron – including three women and a man – have condemned the RAF’s internal investigation into the crisis and said the secretive nature of the non-statutory inquiry had inflicted a “second wound”, according to the Sky News documentary Untouchable: Inside the Red Arrows.

A woman, who claims she was a victim of sexual harassment, told the documentary that the culture was “absolutely toxic” and that “some pilots were untouchable … that’s why it was so dangerous.”

Despite telling her chain of command about what was happening, she decided to leave the air force saying they failed to take appropriate action.

The Times reports that a woman left the service in October 2020 and raised concerns with Air Vice-Marshal Suraya Marshall, who was then an air commodore and head of the Royal Air Force’s officer training college at Cranwell.

Air Vice-Marshal Marshall said she discussed the woman’s case with officers in her chain of command and was assured that she was getting the support she needed.

A formal inquiry was launched in December 2021 after the victim raised the alarm about the Red Arrows with Air Chief Marshal Sir Mike Wigston, then head of the RAF.

Last month, Defence Minister Andrew Murrison told the defence committee that the display team had been “put on notice”, adding: “They are best described as being in special measures.”

It came after a report found the campaign of bullying, sexual harassment and predatory behaviour was “widespread and normalised” in the squadron, with female personnel forced to form groups known as “shark watch” to protect themselves at social events.

Chief of Air Staff, Air Chief Marshal Sir Rich Knighton, offered his “unreserved apologies” following the report’s release, and said he was “appalled” by its findings.

Evidence of possible criminal behaviour was passed to the service police, but they were unable to gather sufficient evidence to begin prosecutions.

The non-statutory inquiry, launched in 2021, found examples dating back to 2017 of team members flashing their genitals, several extra-marital affairs and one case of criminal battery.

The report added that it was highly likely women had to deal with being hounded for sex, unwanted physical contact and derogatory comments about their appearance.

The RAF said any redactions in the report were because the people who spoke “to those conducting the investigation were guaranteed confidentiality and to meet legal obligations to protect personal data (under data protection law)”.

A spokesman said: “The RAF recognise it has taken some time to publish the findings, but it was important to get this right and for the independent team who wrote the report to have time to gather the evidence and let affected personnel have the chance to comment.

“Additionally, there were several extensive clearance and approval processes required before release into the public domain.”

The spokesman added: “Two comprehensive and thorough investigations have been completed relating to unacceptable behaviours within the Red Arrows.

“The findings of the investigations led to action being taken against several individuals, up to and including dismissal from the service.

“This was followed by an unreserved apology from the Chief of the Air Staff and the introduction of many changes within the unit based on the recommendations of the reports.

“As the Chief of the Air Staff has previously stated, any new evidence on unacceptable behaviours anywhere in the RAF will be thoroughly investigated. Where appropriate, he will not hesitate to use the most severe sanctions available to deal with those whose behaviour harms others.”