Recording from his home in a Birmingham suburb, Emdee Tiamiyu promotes himself to thousands of subscribers as YouTube's number one guide to "scholarships, fellowships and japa-ships".

That last word, japa, is the Yoruba term for "to leave", he explains. It is a buzzword among Nigerians eager to escape their country's problems with corruption and poor governance.

"People are looking for alternatives," he says. "They want to escape Nigeria."

Mr Tiamiyu offers advice on navigating immigration systems like the UK's and says for most people the only legal and broadly accessible route is through the education system.

"The student route is more like an answered prayer," he says. It is a "big bracket that's able to take a lot of people, the ordinary people".

A fifth of UK student visas last year went to Nigerians - 120,000 in total, with half for the students themselves and half for partners and children. Nigerians had more family visas for foreign students than any other nationality.

Now, ahead of migration figures on Thursday expected to show that a record 700,000 people came to the UK last year, the government is banning people taking some post-graduate courses - such as master's degrees - from getting visas for their spouses and children.

Mr Tiamiyu says he can understand why the government might want to take action.

Increasingly people are signing up to courses - and willingly paying fees of £22,000 a year on average to UK educational institutions - just to get a visa for themselves and their dependants, the YouTuber says.

"We're beginning to see that a lot of people just hide behind the studentship. So the student thing is not real, it's not like they need the degrees," he says.

Most people genuinely intend to study but the minority who do not is growing, Mr Tiamiyu suggests.

While visas can be cut short if foreign students' attendance and work is not good enough, Mr Tiamiyu says there are still students who are "really not worried about the details of the education".

Instead the course can be a stepping stone to a new life in the UK, allowing them to stay on afterwards for a further two or three years on a graduate visa - or longer on a skilled worker visa if they can get the right job.

During their course, foreign students in the UK are limited to working 20 hours a week in term time, so it's hard to make much money on a student visa. Mr Tiamiyu says the family visas can make it more economically viable, as a spouse travelling with the student can work full-time.

Not all of the marriages are genuine, he says. In a few cases, "people would just team up somewhere in Lagos" before they travel.

But however they enter the country, Mr Tiamiyu says a tough job market means Nigerian students must have real skills and experience to stay in the UK - a long-term visa will ultimately depend on making a genuine contribution.

In the Shropshire town of Telford, there are now around 300 Nigerian residents, many drawn by the University of Wolverhampton campus.

For some of them - such as Rotimi Lawal, studying a master's in mechanical engineering at a cost of £15,000 - the appeal of a UK education is inseparable from the opportunities in its economy.

Rotimi Lawal says he came to the UK to learn and to improve his economic prospects

"Me studying provides an opportunity to also probably work in the UK," he says. With better pay and the chance to make a better life, he says, "I feel it's a smart thing to do."

The university says that banning foreign master's students from bringing their dependants is likely to harm their education.

Dr Rachel Morgan-Guthrie, associate dean for students and education, said: "It's a support network and when students are here and they've got their support networks, they are more likely to succeed."

The YouTube immigration influencer, Mr Tiamiyu, says students who do not care about their education could undermine UK universities.

He thinks some people will think twice about the cost of a UK education if they cannot get a visa for their children or spouse.

"They'll probably go elsewhere," he says. "But if they really need that Oxford degree, they'll still come."

But he says it is important to continue to support legal migration routes, because people are "so desperate".

On his YouTube channel, he has interviewed young people on the streets of Nigeria, asking them if they would take an illegal "japa route" to a foreign country, even if they knew it was risky and might fail.

"You'll be shocked at how many people said they will still take it," he says.