The Chilcot committee has recommended the use of intercept evidence in court - with a number of stringent conditions.
The committee produced its report after hearing from 40 individuals, including judges, security service officials, telecommunications experts and government ministers.
It also received submissions from 12 countries where intercept evidence is admissible in court proceedings.
The question for the review was whether the benefits of allowing intercept evidence to be used in court outweighed the risks and costs.
The Crown Prosecution Service told the committee it would lead to more guilty pleas and fewer abandoned trials; police said there would be a small increase in convictions.
But if intercept evidence were to be admissible, the committee said a legal mechanism had to be in place to ensure the techniques used were not disclosed, putting future operations at risk.
One of the committee members, the former Conservative home and foreign secretary Lord Hurd, explained that the committee's recommendations had implications.
"We are proposing a legal model, a way of doing things, which we think is robust: ie that it won't open up the floodgates.
"But if we're wrong, what will be at stake will not be the spilling out of all our secrets - the risk would be that you lose a case."
Under the proposals, sensitive intercepted material would be withheld from the defence, and disclosed only to security-vetted lawyers, known as special advocates.
The system is already used in some immigration and terrorism cases.
Limits would be placed on the number of recordings required for transcription - to ease the administrative burden.
The crucial point, however, is that the final say on whether a prosecution proceeds with intercept evidence would rest with the interceptors themselves - police and the security and intelligence agencies.
It raises the prospect that a framework could be agreed and approved by Parliament - but rarely used.