Donald Trump’s decision to declassify evidence given by a former British spy about the former US president’s alleged links with Russia led to the disappearance of two Russian sources, according to a court document.

In his witness statement, Steele said the decision to declassify his testimony, taken on Trump’s last day in office, resulted in several Russian sources being exposed and suffering “varying consequences”.

The claimant’s [Trump’s] actions in this regard were truly shocking and arguably constitute one of the most egregious breaches of intelligence rules and protocol by the US government in recent times.”

The statement was released a day after a hearing at the high court, the result of which will determine whether Trump can proceed with his case against Orbis, which Steele co-founded.

In his witness statement released on Monday, Trump said bringing the lawsuit against Orbis was “the only way that I can fully demonstrate the total inaccuracies of the personal data in the dossier”.

In his witness statement, Trump said Ivanka was “completely irrelevant” to the case, adding: “Any inference or allegation that Mr Steele makes about my relationship with my daughter is untrue and disgraceful.”

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