Translators were 'not qualified' for police interview work
Unqualified police interpreters have cost the public thousands of pounds by causing court delays and in one instance the collapse of a case, the BBC has learned.
Three North East forces have spent more than £1.1m with Gateshead-based ITL in the past three years.
Northumbria Police said "action was taken as soon as concerns were raised" over the accuracy of translations.
ITL said it did not accept its services were below acceptable levels.
In addition to Northumbria Police, it provided translators for interviews with the Durham and Cleveland forces.
In one instance the firm's Czech interpreter told a suspect to "not say too much" to police, a BBC Newcastle and Inside Out investigation found.
The interpreter used by police in the interviews was 76-year-old Jan Kartak - a Czech national living on Teesside.
He was unable to explain the police caution in full, meaning the interview was not compliant with the Police and Criminal Evidence Act 1984.
The juvenile suspect was arrested in connection with allegations a woman had been drugged and raped in Stockton.
His co-accused, Jioi Istok and Michal Cina, were tried at Teesside Crown Court for blackmail in August 2016.
The case collapsed due to the quality of the interpretation and a new jury was sworn in.
Their case was heard again in October 2016 and the men were both jailed.
The juvenile suspect was acquitted.
A highly qualified interpreter who worked on the re-interpretation of the police tapes, who asked to remain anonymous, said: "I was absolutely horrified, he was obviously not a qualified interpreter.
"He was making mistakes, making his own little interviews, he wasn't asking what the police officer was asking and he was advising the suspect."
The Crown Prosecution Service said: "During the trial of this case the defence raised an issue with transcriptions of defendant interviews, which had been provided to them by police-instructed interpreters.
"The defence asked the judge for time to have the statements reviewed by their own interpreter and the trial was rescheduled for a date approximately four weeks later to allow for this."
The same interpreter from ITL was used again in a high-profile modern slavery case heard in Newcastle in 2018.
The trial was delayed by three weeks while qualified interpreters reinterpreted the work of Mr Kartak and two other ITL colleagues.
None of the three ITL interpreters involved in the case appear on the National Register of Public Service Interpreters.
A spokesman for Northumbria Police said: "Action was immediately taken as soon as concerns were raised about the accuracy of translations supplied by interpreters from ITL North East Ltd in relation to the modern day slavery case.
"This included interviews being independently re-examined.
"As a result of the concerns raised in the case, Northumbria Police requested a full audit of the qualifications held by all interpreters registered with ITL North East Ltd."
Simon Walker, of the Criminal Law Solicitors' Association, said: "I don't think it can be overestimated as to how significant a problem this is.
"Obviously the knock-on is in expense, inconvenience, stress to all court users and most important of all, I would argue, access to justice and potential for miscarriages of justice."
ITL recruited students at jobs fairs including Eugenija Steponkutė - a Lithuanian student who had been in England for three months when she got a job with the company.
Ms Steponkutė said: "It had only been two or three months since I'd been in England in total so when I came there I didn't get everything the policeman was saying, I tried my best."
Ms Steponkutė has no interpreting qualifications and was given no training by ITL.
ITL is run by Grace Tia Bon Bon.
In a statement, it said: "All interpreters supplied by ITL meet the qualifications required and are suitably registered."
Stephen Bishop, director of the National Register of Public Service Interpreters, said: "I'm really concerned that people are being picked up off the street because they can speak a language and then are being used as interpreters.
Northumbria Police, which leads on interpreting services for the three forces, said: "The contract was awarded to ITL North East Ltd following a tendering process in line with national procurement guidelines and was specific in terms of the supplier's responsibilities to provide both qualified and competent interpreters.
"Following the latest tendering process, the force has instructed a new supplier."
You can see more on this story on Inside Out on BBC One in the North East & Cumbria on 14 January at 19:30.