Urgent steps should be implemented by councils to secure bus services in North Wales following the conviction for fraud of four men.
Express Motors owner Eric Wyn Jones and his three sons face lengthy prison sentences after being found guilty of making fraudulent claims to Gwynedd Council for fake passenger journeys using concessionary bus passes.
They were also found guilty of siphoning more than £500,000 into their own bank accounts and failing to inform the tax authorities.
It is the second time in four years a Gwynedd-based bus company has been found to be making false claims on the concessionary pass scheme.
Two bosses at Llanberis-based Padarn Bus were jailed in 2016 for claiming more money than was owed.

Following the jury's decision to find the Express Motors bosses guilty Arfon AM Siân Gwenllian said: "This type of situation must never be allowed to happen again. My constituents need to be confident that public money will not be misused and to that effect, robust processes need to be put in place as a matter of urgency.
"Looking at the bigger picture, the Welsh Government need to find a sustainable solution to support rural bus service users so that communities in Arfon are not left isolated."
When Padarn Bus folded in May 2014 council officers were forced to work quickly to find other bus companies to operate the bus services.
A similar exercise was carried out at the end of last year when the Traffic Commissioner for Wales revoked Express Motors' operating licence.

The familiar yellow-and-white buses of Express Motors operated an extensive network of services in Gwynedd, Anglesey and parts of Conwy and Ceredigion.
Responding to Ms Gwenllian's call for action a Gwynedd Council spokesperson said: “This was an extremely serious case which involved significant sums money being fraudulently obtained from the public purse.
“As soon as we suspected some possible irregularities at Express Motors regarding the concessionary bus payments, we immediately investigated the matter. As a result of this initial investigation, we then referred the matter to North Wales Police.
“Since then, the Welsh Government has been reviewing procedures for recording and claiming concessionary fares for all local authorities. It is anticipated that these new all-Wales procedures will be implemented in the near future.”
The Welsh Government confirmed this to be the case.
A spokesman said: “Local authorities are responsible for the reimbursement of bus operators under the concessionary fare scheme. A number of measures to detect and prevent similar frauds have already been introduced and we continue to work with local authorities on developing additional measures.”
Referring to the Padarn Bus collapse the council spokesperson added: “When the irregularities at Padarn Bus became apparent, the Council reviewed the procedures at all other bus companies to check that others were not committing the same fraud; they were not.
"However, the findings of that investigation meant that we were able to identify further irregularities within claims for concessionary fares, and we referred our concerns about Express Motors immediately.
"Whilst this was an extremely complex investigation, we are grateful to North Wales Police and the Crown Prosecution Service for their work on the case.”
The four Express Motors bosses are due to be sentenced at Mold Crown Court on October 31.