Sources involved in the investigation and at Kassbohrer (UK), the British arm of the coach manufacturer, told the Independent that the speed limiter on the crashed coach was disconnected deliberately and that it was not the only one.
The sources who examined the company's 38 vehicles at its depot in Hounslow, west London, said 'a number' of coaches were found to be without working speed limiters.
It is understood that papers to be sent to the Crown Prosecution Service give types and numbers of coaches on which speed limiters had been tampered with.
The inquest heard evidence from witnesses who said the coach's brakes appeared to lock after it collided with the rear of a Transit van last November and skidded down an embankment, killing Leslie Golds, the driver, and nine American tourists. Under EU law, all new coaches since April 1989 had to be built with limiters designed to cut off fuel when a vehicle reaches 70mph. The crash vehicle was travelling at 78mph.
The device, which looks like an irregular piece of tubing, works by regulating throttle control once it receives a signal from the vehicle's tachograph that the upper limit has been reached. Another source involved in the investigation said the company had been issued with at least three Department of Transport orders relating to coaches with faulty anti-lock brake (ABS) systems which prevent the coaches being used until the defects are rectified. He and a third source confirmed that other speed limiters on other coaches had been disconnected. The first official said that the company's tachograph records were also being examined.
Directing the jury before they retired for two and a half hours yesterday, the Dover coroner, Richard Sturt, said they could return a verdict of unlawful killing only if they found Mr Golds's driving had been a cause in the deaths.
He said there was not enough evidence of a link between the coach's faulty ABS system and the deaths. Nor was there a 'candidate' within the company whose negligence could be proven to have caused the deaths. However, the jury foreman said the failure of the ABS system was a major contributory factor.
The inquest established that:
Leslie Golds was speeding in bad weather conditions at the time of the crash;
He may have been due to start a rest period when he took the tourists on their trip to Canterbury and Leeds Castle;
Travellers Coach Company had complained to Kassbohrer in Lincoln and Germany the previous February that there were faults with anti-lock brake systems (ABS) in 'most of its fleet' of 12 Kassbohrer Setra vehicles;
Michael Shelton, the regular driver of the crashed coach, had complained that the coach's ABS system and its speed limiter were not working for 13 months before the disaster.
One officer involved in the investigation said: 'The law is quite clear: if the ABS was not working, the coach should not have been on the road. We believe it would have made a difference if it had been working.'
The inquest was told that Mr Golds, 54, was regarded as a first- class and highly responsible driver and that Travellers was positioned at the top end of the luxury coach market.
Evidence from the hearing is likely to be used by American lawyers in lawsuits for huge damages - estimated by one attorney as being a minimum of dollars 1m ( pounds 600,000) per person, rising to a total of dollars 75m ( pounds 50m) when injuries to other passengers are taken into account.
Actions are likely to be brought in the US because Windsor Inc, of St Louis, Missouri, owns Travellers International USA, the company which arranged the excursion to Canterbury and Leeds Castle in conjunction with British Airways. Several people have already included BA in statements of claim in America.
At the time of the accident, Windsor also owned the Travellers Coach Company. That is now in the hands of Steven Wells and Anthony Grayson, who took it over in a management buyout in January.
Paul Hedlund, attorney for almost half the bereaved families, said legal action would 'definitely' follow.
Trevor Golds, the driver's brother, said he was devastated that the jury appeared to blame Leslie Golds. 'Throughout the hearing, everyone has said how professional and meticulous a driver Leslie was,' he said.
But he added that he was pleased the CPS was being involved. He has been critical of the company's safety record in relation to the coach in which Mr Golds died.
He said he and his family were considering civil action against the Travellers Coach Company. It was the first time Leslie Golds had driven the crashed coach and he would have been unaware - and surprised - that the ABS system was not working as disaster struck.
Anthony Grayson, managing director of the Travellers Coach Company, yesterday refused to comment.