Thousands of non-EU migrants will have to provide criminal record certificates before they are allowed to work in the UK under new rules.
Overseas nurses and teachers are among those who will be required to hand over the details as part of efforts to strengthen restrictions on foreign offenders seeking to come to Britain.
The changes will affect those applying to take up jobs which involve working with children and vulnerable adults under the Tier 2 visa route for skilled workers from outside Europe.
Most migrants coming to the UK to work are required by their employers to self-declare that they do not have a criminal record.
Now Tier 2 visa applicants looking to work in sectors including health and social care, education and welfare will have to provide an overseas criminal record certificate as part of an "entry clearance" application.
Failure to provide the relevant documents without an adequate explanation will result in rejection or refusal of a visa application, even when all other criteria are met.
Migrants affected by the new rules will have to provide criminal record checks from any countries they have lived in for more than a year in the past decade.
However, the requirement could be waived in circumstances where it is deemed not "reasonably practicable" to obtain the certificate, such as if a particular country or authority does not produce the documents.
The Government can automatically refuse entry for applicants with a custodial sentence of four years or more.
Those given shorter jail terms can be barred for up to 10 years from the end of the sentence.
Immigration Minister Robert Goodwill said: "Our priority is keeping families, communities and our country safe.
"Foreign criminals have absolutely no right to be working with society's most vulnerable.
"While we already reserve the right to refuse a visa to anyone who is convicted of a criminal offence, the introduction of overseas criminal record checks for those looking to work with children and vulnerable adults add an extra safeguard."
The new requirement, which will take effect next month, was one of a number of changes to immigration rules set out by the Home Office on Thursday.
Another measure will tighten the regime for migrants who remain in the country after their leave to enter or remain has expired.
Currently "over-stayers" are given a 90-day grace period before a 12-month ban on re-entering the UK kicks in.
Now this grace period is being shortened to 30 days.