A former Boeing employee, who was found dead in March, accused the company of “countless” violations of US law in testimony given just before his death.

John Barnett claimed the firm tried to “eliminate” quality inspections at a plant that makes 787 planes.

The former quality control manager had been giving a formal legal deposition against the plane manufacturer.

The 62-year-old’s death after two days of testimony was from a “self-inflicted gunshot wound”, officials said.

Boeing says it was “saddened” by Mr Barnett’s death, but said the issues he raised had been reviewed and addressed.

The aerospace giant’s safety standards are currently under the spotlight, in part due to an incident in January when a disused door fell off a brand new 737 Max shortly after take-off.

The transcript of Mr Barnett’s deposition has now been released by his lawyers. The lengthy document runs to more than 140 pages.

Mr Barnett had worked for Boeing for more than 30 years before his retirement on health grounds in 2017. He subsequently filed a lawsuit against the company, claiming he had suffered retaliation from managers after raising a number of serious safety concerns, a charge the company denies.

The bulk of Mr Barnett’s deposition focuses on the period from 2010 onwards, after he had moved from Boeing’s facility in Everett, Washington to what was then a brand-new factory in North Charleston.

The plant had been set up to help assemble the 787 Dreamliner, a state-of-the-art airliner used mainly on long-haul routes.

Mr Barnett had previously told the BBC and others that managers there had routinely ignored formal procedures in order to build planes as quickly as possible.

In his deposition, he provided more detail on these allegations, in support of his legal complaint that he had been “denigrated, humiliated and treated with scorn” by senior managers, who had subjected him to a gaslighting campaign, and created a “hostile work environment” as a result of his actions.

A key part of his testimony focused on the alleged falsification of records relating to problems within the production process and in particular the logging of defective or substandard parts.

He claimed employees had been under pressure to circumvent establish procedures, set out in Boeing’s own Quality Management System, to save time. A common theme within the factory, he said, was: “We don’t have time to follow processes, we’re building airplanes”.

This, he said, had allowed “an awful lot” of faulty parts onto the production line, while others had simply been lost. These included two large sections of aircraft fuselage, which “weren’t anywhere to be found”.

In one specific instance, he claimed a contaminated and faulty tube designed to work in an oxygen system had been removed from a scrap bin and might have been installed on an aircraft that was now in service.

Such parts normally had to be carefully sterilised to reduce the risk of unwanted chemical reactions. Without that, he said, there was a risk that if the system was activated, it could cause an explosion that would “bring the whole plane down”.

He suggested that there had been “countless” occasions on which paperwork had been falsified, and agreed with his lawyer’s suggestion that each violation of procedure amounted to a “criminal offense and felony”.

Mr Barnett was also deeply critical of what he saw as a drive at the South Carolina plant to reduce quality control inspections, again to speed up the manufacturing process.

“So the push for probably the last 15 to 20 years at Boeing is to eliminate quality [inspections]”, he said. “But when here in Charleston they put that push on steroids”.

Boeing’s own lawyers focused more on Mr Barnett’s claims that he had been retaliated against, and appeared to question his assertion that his safety concerns had not been taken seriously at the time.

In a statement given to the BBC, Boeing said: “We are saddened by Mr Barnett’s passing and our thoughts continue to be with his family and friends.

“Boeing reviewed and addressed quality issues that Mr Barnett raised before he retired in 2017, as well as other quality issues referred to in the complaint. Engineering analysis determined the issues he raised did not affect airplane safety”.

It also drew attention to a decision made earlier in Mr Barnett’s case, in 2020, in which the US Occupational Safety and Health Administration concluded the company had not breached whistleblower protection law.

It added: “We appreciate employees who raise their voice, and we have systems in place to encourage them to speak up confidentially or anonymously.

“To ensure the safety, quality and conformance of our products, we investigate all allegations of improper behaviour. We then work diligently to address them and make improvements.”

Mr Barnett’s lawsuit is expected to continue. It will be taken forward by his mother Vicky Stokes and his brother Rodney Barnett as representatives of his estate.

The case is now expected to go to trial in September.