Peter Mandelson's links to a Chinese minister, a Russian oligarch and an Israeli former general were among concerns raised by security officials, it has emerged.

The UK's vetting agency is reported to have flagged the peer's associations with a series of individuals when it concluded he should be denied clearance.

It was revealed last month how UK Security Vetting (UKSV) recommended against granting Mandelson the developed vetting necessary for his appointment.

But the Foreign Office went on to give him clearance to become Britain's ambassador to the US despite that advice.

The Prime Minister sacked Olly Robbins, the top official at the Foreign Office, for not disclosing the security concerns to ministers.

According to The Guardian, Lord Mandelson's ties to Lan Fo'an, China's minister of finance, Oleg Deripaska, a Russian billionaire, and Tamir Hayman, one of Israel's former top spy chiefs, were all flagged by UKSV.

A £1million loan that Lord Mandelson received to invest in an Israeli start-up is also said to have been among the concerns raised by the agency, while UKSV is reported to have noted the peer had a very close relationship with a fourth individual, who is British, that could be compromising.

The revelations will lead to questions about whether there was any national security risk posed by Lord Mandelson's seven-month spell in Washington DC.

It also comes amid a row between Parliament's intelligence watchdog and the Government over the release of files relating to Lord Mandelson's appointment.

The Intelligence and Security Committee this month claimed some documents are being 'withheld' from MPs and the Government is redacting files 'too broadly'.

Lord Beamish, the chair of the committee, said Lord Mandelson's vetting file was one example of a document that had been kept back.

The Tories accused the Government of trying 'to pull the wool over the public and Parliament's eyes'.

But the Cabinet Office said it is committed to complying with the 'humble address' motion demanding the release of the Mandelson files 'in full'.

A first tranche of files was published in March and a second batch of documents is expected to be released next month.

As part of its work in collating the files for publication, the Cabinet Office last month confirmed that UKSV did not recommend granting developed vetting clearance to Lord Mandelson.

Sources told The Guardian that concerns about the peer's historical relationships with other individuals were contained in a nine-page UKSV summary of Lord Mandelson's vetting file in January last year.

Mr Lan has been China's finance minister since 2023 and greeted Keir Starmer on the runway in January this year during the Prime Minister's visit to Beijing.

It is claimed that Lord Mandelson and Mr Lan spoke several times a year, but had not done so for 12 months before the peer's vetting process began.

Mr Deripaska was sanctioned by the UK Government following Russia's full-scale invasion of Ukraine in 2022.

Lord Mandelson's controversial friendship with the oligarch has been publicly known for almost two decades.

Mr Hayman is the director of the Institute of National Security Studies thinktank in Tel Aviv and was previously head of Israel's military intelligence directorate.

He is reported to have spoken with Lord Mandelson bimonthly.

The peer is also said to have had another Israeli connection identified by UKSV, relating to his stake in Moon Active - the Tel Aviv-based company that creates online games.

It is claimed that Lord Mandelson received a £1million loan from a businessman to acquire shares in the company.

Sir Keir was forced to sack Lord Mandelson as US ambassador in September last year over his friendship with paedophile financier Jeffrey Epstein.

The PM has been left reeling by the Mandelson scandal and is now fighting for his political future following Labour's dismal local election results. 

Liberal Democrat leader Ed Davey said: 'The fact that the Government is still trying to hide the truth when it comes to Mandelson is an utter disgrace.

'I can only imagine how angry Keir Starmer would be about it if he weren't running the Government.

'The responsibility for the hiring of Peter Mandelson lies at the door of the Prime Minister.

'No10 knew full well about Mandelson's business relationships with China and Russia, and indeed with Jeffrey Epstein too.

'Glaring warning signs were wilfully ignored, driven by a desperate desire to pander to the bully in the White House rather than protect British interests.'

The Cabinet Office, Foreign Office and represenatatives of Lord Mandelson have all been contacted for comment.