Independent reviewer of terrorism legislation says he is quite sure US government and agencies 'had something to do with it'

The US government and its intelligence agencies were influential in the UK government decision to introduce a highly controversial new generation of secret courts, the independent reviewer of terrorism legislation has told MPs and peers.

David Anderson QC told parliament's joint human rights committee on Tuesday that he could not know whether the US was the driving force behind the justice and security bill but, after a series of conversations during a visit to America, he concluded: "I am quite sure they had something to do with it."

Anderson, who told the committee of MPs and peers on Tuesday that the bill was "disproportionate", added that he had been left in no doubt that US officials were genuinely alarmed by the English courts' willingness to disclose information the CIA had passed to British intelligence agencies in the case of Binyam Mohamed, the UK resident who was tortured and rendered to Guantánamo Bay.

Anderson said he was told in Washington that the future of UK-US intelligence sharing depended upon the Britain's ability to "sort this one out" before more material was made public.

"It was said to me that there would have to be a reassessment of the intelligence relationship," Anderson said.

He claimed that what angered US officials most was that an English court was prepared to overrule the view of a foreign secretary – a reference to David Miliband's evidence during the Mohamed hearings in 2008 that disclosure would damage UK intelligence relations with the US.

The sensitive material disclosed in the Mohamed case was a report supplied by the CIA in which they detailed the manner in which he was being tortured after being detained in Karachi in 2002. It was sent to MI5, who then dispatched one of its officers to Pakistan to interrogate Mohamed.

There was "no rational basis" for Miliband's claim, the high court ruled, adding that the CIA material should be disclosed "for reasons of accountability and the rule of law in the United Kingdom".

Anderson was asked by the Labour peer Lady Kennedy how, under the bill, Britain could honour its obligations under the UN convention on torture, which obliges countries to act if they have evidence. He replied that "accepting a principle" might lead to a "pragmatic cost" – referring to the prospect of the US cutting on the amount of intelligence it passes to Britain.

Anderson reiterated his view that the bill, while addressing a genuine problem, did so in a "disproportionate" manner. He said judges – and not ministers, as the bill states – should have the discretion to decide whether evidence should be heard in secret – so-called closed material proceedings (CMP) – and the bill should state clearly that such secrecy should be used only as a last resort.

Depriving judges of the discretion over whether to use CMPs would not bolster public confidence in the judiciary or the UK's intelligence and security agencies, Anderson warned, although he accepted that the proposals were about "more than the convenience of the intelligence services".

The government argues that CMPs are needed to prevent courtroom disclosure of sensitive evidence from causing damage to the so-called "control principle" governing intelligence shared between states.

Secret evidence, which is already used in terrorism-related immigration tribunals, allows government lawyers to rely on evidence that cannot be seen by victims or claimants, or their lawyers. The evidence can be seen by security-vetted barristers known as special advocates, but they cannot discuss what they have seen. The system is widely regarded as inherently unfair and would inevitably lead to legal challenges.

Anderson suggested that if the bill became law, it should be subjected to annual review. Critics of the bill warned that secret courts could be introduced in more and more cases unrelated to terrorism.