A bus company which provided a school transport service and tried to cover up two wheels falling off one of its coaches has had its licence revoked with immediate effect.
Tacsi Gwynedd, which operated as Huw's Coaches, was also accused of trying to mislead and intimidate inspectors.
Traffic Commissioner for Wales Nick Jones said the ban was due to an "an unjustifiable risk" to the public.
The company said it had been "unfairly targeted" by the authorities.
A spokesman said the incidents happened over a period of months with an "unexpectedly high" number of inspections, and that the decision could lead to the loss of eight jobs.
The Caernarfon-based operator's licence was withdrawn with effect from 23:59 BST on Sunday.
Owner Huw Edwards and his son Sion will be disqualified from running bus firms in the future and transport manager Alan Vaughan Owen has "lost his repute", Mr Jones said.
Gwynedd Council confirmed it was working to find temporary replacement services for school and public services formerly operated by Huw's Coaches.
In a decision published on Friday, Mr Jones said the firm's management had been involved in a campaign to frustrate and "impede" attempts to investigate it.
This included the intimidation of Driver and Vehicle Standards Agency staff and "false claims" that an incident which involved two wheels falling off a bus was in fact due to a "tyre blow out".
"The combination of poor vehicles, deliberate false claims as to incidents and calculated attempts at intimidation are such that I cannot allow buses to continue to be run," said Mr Jones.
"The operator no longer satisfies the requirement to be of good repute, it no longer satisfies the requirement to have financial standing and it no longer satisfies the requirement to be professionally competent."
He added: "Road safety concerns are immediate and significant."
The Tacsi Gwynedd spokesman added it "completely and utterly denied" the claim of intimidation.
"(It) had arisen from an incident in which a member of staff had seen a stranger reversing one of the company's buses toward the depot gate, without realising that the person in the bus was a member of DVSA staff," he said.
Company officials also denied that vehicles were allowed on the road in an unsafe condition and are considering appealing.