The home secretary has touted the idea of getting rid of jury trial in terror cases leaving the door open for judges to pay a more investigative role.
Mr Clarke was giving evidence to the home affairs select committee
Charles Clarke said he was "not an absolute fan of the adversarial system of British justice".
He said he was prepared to have a look at "other systems" but pledged any plans would involve wide consultation.
Lord Carlile, independent reviewer of government terror laws, said he opposed moves to a new judicial system.
This was despite accepting that some courts in Northern Ireland sat without juries and there the "quality of justice was very high".
Lord Carlile, a top QC and ex-Lib Dem MP, said there was a case to be made for judicial supervision of procedures that led to the "detention of persons without charge".
In some EU countries judges play a more investigative role and Mr Clarke acknowledged, in evidence to MPs on Tuesday, any change in the UK would be "absolutely enormous and would require a massive, massive shift and very wide consultation".
Mr Clarke also told the Commons select committee that he might consider allowing phone tap evidence in future criminal trials.
He said last month he had decided not to allow such a move because of fears it would jeopardise techniques used by British intelligence.
But on Tuesday he added: "I do not think it would be right to rule out forever using intercept as evidence."
On Sunday EU foreign policy chief Javier Solana said phone-tap evidence works in other EU countries' courts.
"It would be naive not to use this technological thing that we have at our disposal," he said.
Sir Ian Blair, the newly-appointed Metropolitan Police commissioner, has also said he is in favour of phone-tap evidence.
Under the Anti-Terrorism, Crimes and Security Act 2001, foreign terror suspects can be detained in British jails without trial or charge.
Several suspects have been detained under these powers because evidence against them was deemed too sensitive to be heard in court.
Some of this evidence is believed to be telephone intercepts.
Human Rights group Liberty has argued that if intercept evidence could be heard, these detainees could be brought to trial.
Mr Clarke has been forced to change the regime of detention without trial after Law Lords ruled it illegal.
He has opted for a system of "control orders" whereby suspects, both British and foreign, can be held under house arrest or surveillance.
These orders will again involve a UK opt-out of parts of the European Convention on Human Rights.