A “small” number of wealthy foreign investors were “potentially at high risk” of having links to corruption or serious organised crime, a review of so-called golden visas has found.

Home Secretary Suella Braverman set out the findings after the Government shut down the tier 1 investor visa route last year amid security concerns, revealing 10 Russian oligarchs who used it have since been sanctioned as a result of the invasion in Ukraine.

Those eligible for the visa, launched in 2008, needed to have at least £1 million in investment funds in active and trading UK registered companies.

Successful applicants were able to work or study in the UK for up to five years and apply to settle in the country after making further investments.

But the scheme was put under review over fears the system could be exploited because not enough background checks were made on applicants, amid claims by Labour former minister Chris Bryant that visas were being handed out to “dodgy Russian oligarchs”.

In a written statement to Parliament published on Thursday, Ms Braverman said: “I can confirm that the Home Office considered the cases of the 6,312 tier 1 (investor) migrants and tier 1 (investor) adult dependants who obtained leave between the launch of the route on 30 June 2008, and the introduction on 6 April 2015 of a requirement to open a regulated UK bank account before applying for a visa under the route.

“The review of cases identified a small minority of individuals connected to the tier 1 (investor) visa route that were potentially at high risk of having obtained wealth through corruption or other illicit financial activity, and/or being engaged in serious and organised crime.”

Ms Braverman stressed this only “implies that a particular individual potentially poses a risk of having connections to criminality; it does not mean guilt has been proven”, adding that police had been given access to the information and were “taking action as appropriate”.

Immigration action “has and is being considered” for “high-risk individuals” and 10 oligarchs “who had previously used this route” had already been sanctioned as part of the Government’s response to “Russian aggression in Ukraine”, she said.

The statement was published five years after a review of golden visas was announced by then home secretary Amber Rudd in the wake of the 2018 Novichok poisonings in Salisbury.

The decision to close the visa scheme in February 2022 came amid concerns over Moscow’s influence in the UK as tensions rose over the impending conflict in Ukraine.

In her statement, Ms Braverman insisted her department is “robust in refusing leave where this is appropriate”, but said it had found there were “inherent difficulties” with the scheme “both in terms of security and economic value”, adding: “I am determined this Government will ensure such mistakes are not repeated.”

Labour branded the response “totally inadequate” while the Liberal Democrats said it was “farcical” and called for the review to be published in full.

Shadow home secretary Yvette Cooper said ministers have “finally recognised and admitted that 10 of those sanctioned following Russia’s invasion of Ukraine had come to the UK on golden visas” but had failed to provide answers to “basic questions” raised about the scheme, adding: “It is disgraceful for the Home Secretary to dodge scrutiny in this way.”

She said Ms Braverman should come to Parliament and publish a “far more detailed report” answering the “national security questions” posed by the findings.

Layla Moran, foreign affairs spokeswoman for the Liberal Democrats, claimed the statement “stinks of a cover-up”, adding: “We need to know to what extent the Government let Kremlin-linked oligarchs treat this country as their playground. If the Conservatives have nothing to hide, then they will have nothing to fear. The review must be published in full, right away.”

The review “did not find evidence of a systemic failure across financial institutions to carry out appropriate customer due diligence checks” on visa applicants in the period in question. But there was evidence of “applicants seeking out and exploiting financial institutions that had the weakest customer due diligence controls”, Ms Braverman said, noting that some of the organisations involved have since been fined by the Financial Conduct Authority.

The immigration system was “not as well equipped to respond” to the risks posed by the visa route and would require caseworkers to have “specialist expertise” in detecting potentially complex cases of financial crime, according to her statement on the review.

The Home Secretary said alternative visa options were being considered “carefully” and any future investment-based scheme “must not offer entry solely on the basis of the applicant’s personal wealth”.

She added: “We must ensure that kleptocracies such as Russia are not able to act with impunity overseas. That is why the UK has taken strong action since the start of the war and why we will continue to do so in the years to come.”