Police should be able to quiz suspects after they have been charged, the attorney general has suggested.
Lord Goldsmith has not seen evidence yet to back 90-day detention
Lord Goldsmith said he favoured such a change in the law for terror suspects - and possibly other suspected criminals.
He added safeguards would be needed to ensure suspects were not "browbeaten time and time again" by police.
Lord Carlile, the official reviewer of UK anti-terror laws, welcomed the idea but warned against police using minor charges as "holding charges".
He told the BBC: "We don't want to have the British police charging people with something in terrorist terms that is the equivalent of riding a bicycle without lights and then interviewing them months later on much more substantial issues."
Under the Police and Criminal Evidence Act 1984 (PACE), a suspect is not allowed to be interviewed after they have been charged, except in special circumstances.
These include when it is necessary to prevent or minimise harm to someone, to clarify an ambiguious statement, or when it is in the interests of justice for the suspect to be asked about some new piece of evidence.
The UK's most senior police officer, Sir Ian Blair, called for legislation allowing the questioning of terrorist suspects after charge earlier this month, along with a range of anti-terrorist laws.
Lord Goldsmith was speaking about the possibility that ministers might try again to get a change in the law through Parliament allowing terrorist suspects to be held for up to 90 days, before they are charged.
'More time needed'
Police say they sometimes need much more time because of the complexities of gathering evidence from computer hard-drives, mobile phone records and investigating fake identities.
But attempts to get it through Parliament last year failed after opposition from the Conservatives, the Liberal Democrats and Labour rebels on civil liberties grounds.
Instead a compromise was reached, extending the old 14-day holding period to 28 days.
The prime minister indicated last week he still favoured longer pre-charge detention periods, but Lord Goldsmith said he had not yet seen enough evidence to justify the extension.
Instead he said he favoured a change in the law, so police could still question suspects - both in terrorism cases and others - after they had been charged.
"While terrorism is top of the agenda I don't think that it needs to be restricted to that," he said.