The head of the National Crime Agency (NCA) has said that the police should prioritise current cases over allegations of historical sex abuse.
Her comments come after a controversial investigation into a VIP paedophile ring alleged to have been active more than 30 years ago was dropped on Monday.
Speaking to the The Times, Lynne Owens said the police had a "responsibility" to catch current offenders.
She said: "Our priority has to be offending that is happening today because that's the only way that we can protect future victims."
Although she said the police needed to find a way to support victims of historical abuse, she said: "If there is an offender offending today, I think we need to be in a position to be able to respond to that swiftly and decisively to prevent that offending behaviour."
The director general of the NCA acknowledged that for victims, whenever the abuse occurred, the feelings were likely to be as raw as when they happened.
But she added: "The difference between the two is if it's still happening, we have a responsibility to try and catch the offender now, at this moment in time. So in our response, we have to make sure that we get the balance between those two right."
She also questioned whether an in-depth criminal investigation was appropriate if an alleged offender was dead or deeply unwell.
A fiercely-criticised Metropolitan Police probe, Operation Midland, was launched in November 2014 after claims that boys were sexually abused by a number of public figures more than 30 years ago.
It cost £1.8 million up to November 2015 and did not lead to a single arrest, but saw raids on the homes of 92-year-old D-Day veteran Lord Bramall and the late Lord Brittan.
Ex-Tory MP Harvey Proctor, who furiously denied any involvement, was interviewed under caution twice and had his home searched but has now been told he will face no further action.
The late former prime minister Edward Heath was also named in connection with the inquiry.
Scotland Yard deputy assistant commissioner Steve Rodhouse defended the investigation and said it had been "handled well".
An independent, judge-led inquiry has already been announced into how Scotland Yard has dealt with historical sex abuse investigations involving public figures.
Former High Court judge Sir Richard Henriques will examine a number of inquiries, including Operation Midland.