A "health tourism" culture has been blamed for the millions of pounds being spent hiring interpreters each year in Northern Ireland's health service.
The cost of bringing in translators rose by almost 20% in the past three years, reaching £3.4m in 2015/16.
In total, £9.3m was spent between 2013/14 and 2015/16.
The biggest spender by far is the Southern Health Trust which last year forked out a total of £1.57m on translators - and £4.2m across the three years.
Next up was the Belfast Trust which spent £960,000 last year, followed by the Northern Trust at £451,000 in 2015/16.
The figures were obtained by former Health Minister Edwin Poots.
The DUP MLA said the costs were spiralling out of control.
"There are many cases where translators have been hired and not required, and this is a waste of our taxpayers' money," he said.
"The total cost seems to be very high and I can only imagine what the next year's costs will be, given the trend over the past three years."
Mr Poots also questioned if each of the health trusts were proactive enough in reclaiming costs for treating EU nationals from their own governments.
He said: "Our health trusts are spending millions on the costs of interpretation each year, some of it justified and some not.
"Due to the high standards of the healthcare system in the UK, I believe there is an element of health tourism going on which could be putting a major drain on our health budgets.
"There are many foreign nationals working legitimately in Northern Ireland and paying all the appropriate taxes and health costs. However, there are others who are not but that are receiving care from our hospitals.
"In turn, our health trusts should be claiming back the cost of care from those countries whose people we are treating here.
"However, I recently asked how much our health trusts in Northern Ireland claim back from countries in the European Union, and in my opinion it was low." Figures obtained by Mr Poots show that in 2015/16, health trusts here reclaimed a total £635,591 from European countries. Mr Poots says this could be a lot higher and urged trusts to be more proactive.
A spokesperson for the Department of Health said interpreting is "essentially a demand-led service".
He said: "The key driver for such costs is the number of requests for interpretation received by each Trust - the number of requests is likely to be influenced by the geographical location and/or size of the Trust concerned. HSC Trusts are required to assess the entitlement of visiting patients to access publicly-funded health services, with reference to the 2015 Provision of Health Services to Persons Not Ordinarily Resident Regulations. Where a patient or the service provided to them is not exempt from charge under these regulations, trusts will seek to recover treatment costs directly from the patient.
"For EEA nationals insured by another EEA Member State (for example, under the European Health Insurance Card scheme (EHIC)), costs are recovered by the British government on behalf of the Devolved Administrations.
"This money is paid back to the Treasury, and HSC Trusts receive a proportion of all EHIC treatment costs which they report. Non-EEA nationals applying for a visa lasting six months or more are required to pay a health surcharge which entitles them to access health services. The Department of Health receives its share of this funding."