A shadow industry of law firms and advisers is charging thousands of pounds to help migrants pretend to be gay in order to stay in the UK, the BBC has found.

In the first part of a major undercover investigation, we reveal how migrants whose visas are due to run out are being given fake cover stories and instructed in how to obtain fabricated evidence, including supporting letters, photographs and medical reports.

They then apply for asylum claiming to be gay and in fear for their lives if they return to Pakistan or Bangladesh.

In response to our findings, the Home Office said: “Anyone found trying to exploit the system will face the full force of the law, including removal from the UK.”

The UK’s asylum process offers protection to people who can’t return to their home countries because they would be in danger.

But the BBC News investigation reveals the process is being systematically exploited by legal advisers extracting fees from migrants who want to stay in the country.

These are often people whose student, work or tourist visas have expired, rather than those who have just arrived in the country on small boats or through other illegal routes.