A visa scheme which allows foreign investors a fast-track to settlement in the UK is to be suspended as part of a crackdown on money laundering.
Tier 1 investor visas were introduced in 2008 for those willing to invest millions of pounds into the country.
A £2 million investment could secure a visa and indefinite leave to remain after five years.
But the Home Office said the scheme would be suspended from midnight on Friday amid ongoing efforts to tackle serious organised crime.
The suspension will end once toughened measures have been put in place, ministers said.
Immigration minister Caroline Nokes said: "The UK will always be open to legitimate and genuine investors who are committed to helping our economy and businesses grow.
"However, I have been clear that we will not tolerate people who do not play by the rules and seek to abuse the system.
"That is why I am bringing forward these new measures which will make sure that only genuine investors, who intend to support UK businesses, can benefit from our immigration system."
More than 1,000 Tier 1 investor visas were granted in the year ending September 2018.
The Home Office said reforms to the scheme would include applicants having to provide comprehensive audits of all their financial and business interests.
These audits will have to be carried out by suitably regulated UK auditing firms which have no involvement with any qualifying investments or the visa application.
Applicants will also be required to prove that they have had control of the required £2 million for at least two years.
Other measures will aim to increase the benefits to UK companies by excluding investment in Government bonds and strengthening the rules to ensure investments are made in active and trading UK companies.
There will also be a new provision for pooled investments, which are supported by Government, to back projects with a clear economic benefit to the UK, such as supporting small and medium enterprises.
The changes to the scheme are part of wider reforms to the visa system.
The Home Office is also replacing the Tier 1 Graduate and Entrepreneur visa routes with a Start-up visa route, announced in June, and the Innovator visa route.