Police chiefs have insisted they needed to hold terror suspects for longer without trial but rejected any move towards Guantanamo Bay-style internment.
There was confusion after the head of the Association of Chief Police Officers (Acpo) called for a detention period "as long as it takes".
Ken Jones was subsequently forced to clarify his position after civil liberties campaigners seized on the comments to accuse him of proposing internment.
He stressed he had no desire for indefinite detention and accepted the need for a time limit.
Acpo is telling the Government it needs an increase to the 28-day time limit on detention without charge or trial because of the global scale of terror investigations and the need to arrest suspects early.
But Mr Jones said: "We are not arguing for some kind of Guantanamo nonsense for the UK. We do not want internment. That would be crazy."
He added that Acpo wanted the checks and balances to be stepped up to reassure the public before the issue of time limits was discussed again.
But he said police chiefs did not want to start proposing timescales themselves. "Let's get increased oversight mechanisms of some sort, then it's up to Parliament to talk about what an upper limit might look like," he said.
Mr Jones said earlier police were struggling to cope with the 28-day limit which MPs eventually agreed.
"We are now arguing for judicially supervised detention for as long as it takes," he said in an interview with The Observer. "We are up against the buffers on the 28-day limit. We understand people will be concerned and nervous, but we need to create a system with sufficient judicial checks and balances which holds people, but no longer than a day necessary."
