Yasmin - not her real name - came from Iran to study for a master’s degree at a new university in the UK, but she was "shocked" to find many of her fellow students had limited English, and only one or two were British.
"How is it possible to continue this coursework without understanding a British accent or English properly?" she tells BBC File on 4.
Most students paid other people to do their coursework, she explains, and some would pay people to register their attendance at lectures for them.
Yasmin's experience reflects a growing concern. The University and College Union (UCU) says some institutions are overlooking language skills to receive high fees from overseas students, and one professor tells us 70% of his recent master’s students had inadequate English.
Universities UK - which represents 141 institutions - rejects the claims and says there are strict language requirements for students coming from abroad.
Jo Grady from the UCU, which represents 120,000 lecturers and university staff, says it is an open secret that students who lack English skills find ways to come to the UK to study.
"When we speak to members we hear about the tricks that are pulled in order to have people pass the relevant language test and get on to courses," she says.
About seven out of 10 students studying on master’s courses in England are now from overseas, far higher than on other types of higher education course, says Rose Stephenson from the Higher Education Policy Institute, an independent think tank.
In England, university tuition fees for undergraduate domestic students are capped at £9,250, rising to £9,535 per year in 2025-26. Each of the other UK nations set their own fees. But fees for overseas students studying in England have no upper limit.
"You can charge a foreign student as much as they're willing to pay," says Ms Stephenson.
Post-graduate fees are not capped either, so a master’s degree at an elite university could cost £50,000.
Because undergraduate tuition fees for domestic students in England have not kept up with inflation, there has been a real-terms cut in university funding, says Ms Stephenson - with international students, in effect, subsidising the below-cost fees of home students.
One whistleblower who worked at an agency which recruits overseas students for UK universities told us agents would target families abroad who had the money to pay.
The whistleblower - who has previously also spoken to the Sunday Times - said: "We knew that those universities are increasingly desperate and would go along with our plans without much scrutiny into how those students were being found.
"No independent party is looking at the grades or the examinations. It's the Wild West, in a way."
The whistleblower worked for Study Group, one of dozens of education providers feeding the UK university system, and taking large fees in the process.
Based in the UK, Study Group is a registered provider which says it works for more than 50 universities with a network of 3,500 agents in 99 countries.
Study Group strongly disputes the whistleblower's claims, saying overseas students earn their places on merit. It adds that any decision to admit a student on to a course is taken by the university, not Study Group, and rejects the claim that entry criteria are waived for any reason.
It says courses it runs are robustly "scrutinised by partner universities".
Yasmin paid £16,000 for her course in international finance at a university in southern England. She later found out that of the 100 students on most of her modules, "maybe 80 or 90 of them bought assignments" from so-called "essay mills" based overseas. In England it is a criminal offence to complete work for a student which they can pass off as their own.
When Yasmin told her tutor what was happening, he took no action. Yasmin says she now feels her master’s degree has been "devalued".
A Russell Group university professor, who has taught at several universities and wants to remain anonymous, echoes Yasmin's concerns. He tells File on 4 that 70% of his students at master’s degree level over the past five years did not have sufficient English language skills to be on the course.
"There have certainly been occasions when very simple questions have not been able to be understood by students who I am teaching," he says.
The professor told us he has had to adapt his teaching technique, and says students even use translation apps in class. But he insists fault does not lie with international students themselves, who are mostly trying their best, and says the situation varies from subject to subject.
They pass, he says, because courses are often assessed through assignments, rather than exams. Some students use essay mills and pay for others to write their work or, increasingly, use artificial intelligence (AI). Both methods, he says, can defeat current anti-plagiarism software.
UCU’s Jo Grady says it is hardly surprising some students with poor English skills feel they need help from other people, or even use AI to do their work, as an "act of desperation".
She says her members tell their managers that enrolling students without good English "is a bad idea… they will struggle, and we will also struggle to teach them". However, she says "university managers and leaders pursue it regardless, because of the money and income it will bring in".
Some universities are in financial crisis, says Ms Grady, and have become dependent on high-fee paying overseas students who "pay eye-watering sums of money".
"Institutions are chasing money. They're not necessarily chasing the best candidates. And it's a corruption of what higher education should be."
Vivienne Stern, chief executive of Universities UK, rejects the suggestion some overseas students are being allowed on courses with poor English language skills as a way of boosting income.
She says universities carry out strict checks on those they enrol - including minimum language levels, as set by the UK government.
"Students will need to be able to afford the fee to study in the UK, but beyond that it’s a question of taking students who apply, and applying a merit-based criteria," she says. "It is absolutely central that this is a system that people trust."
Ms Stern says international students are attracted by the quality of the UK's universities and says it would be "unwise" to rely on international income to fund domestic education and research, because overseas student numbers could be affected by geopolitics or shifts in exchange rates.
Meanwhile, international student numbers are falling. Data on UK student visa applications from the first half of this year shows there has been a 16% decline in applications, resulting in a loss of income for some institutions. This drop is, in part, being attributed to changes in UK student visa rules preventing most postgraduate students from bringing dependents.
It is contributing to the worst financial crisis for universities since fees were first introduced. Last month, the government regulator, the Office for Students (OfS), estimated that by 2025-26, 72% of universities could be spending more money than they have coming in, and warned that "rapid and decisive action is necessary".
The Department for Education told the BBC a reliance on overseas students has been identified as a risk, and many universities will have to change their business models, adding that the government is committed to managing migration carefully.