The Ministry of Justice admitted it has spent more than £20 million pounds on interpreters and translators in the last two years, fuelling concerns over the impact immigration is having on the public purse.
The figure included £11.8 million spent in 2007/08 which was higher than MPs had previously been told in a series of parliamentary written answers.
One, to Dominic Grieve, the shadow justice secretary, last year was more than £1 million short of the true figure, while Damian Green, the shadow immigration minister, was told spending had been £11.4 million.
Another, in 2008, only had figures for translation services and not interpreters while the fourth suggested more than £28 million had been spent in that year.
Mr Green said: “These mistakes cast a further cloud of the accuracy of Government figures.
“However you present them, it shows how expensive the need for interpreters in the legal system has become as more and more people in this country are simply unable to understand English.”
The spending figures refer to services for victims of crime and other court users but not suspects, which is funded by the police and Home Office.
A Ministry of Justice spokesman said: “To ensure that justice is done efficiently and effectively, defendants, victims and witnesses must understand the questions they are asked and be able to give an accurate account of events. It is clearly not right to question a defendant who doesn’t understand English without an interpreter present.
“Interpretation and translation services are provided on the basis of need. Costs are kept to a minimum and have not risen in recent years. The Office of Government Commerce (OGC) has established a framework for translation and interpretation to ensure that these services are secured in the most cost efficient manner possible across government.”