Crime figures are likely to rise significantly if tough checks are brought in on how the police record them, according to the head of the statistics watchdog.
Sir Andrew Dilnot expressed regret that his UK Statistics Authority (UKSA) had not highlighted major problems with the information earlier.
He insisted it is crucial that proper auditing procedures are introduced to check information is accurate and not being manipulated.
Sir Andrew issued the warning as he gave evidence to MPs after the UKSA withdrew its "gold standard" mark from police crime figures.
The move last week means the data for England and Wales, published by the Office for National Statistics (ONS), effectively come with a health warning.
Sir Andrew told the Public Administration Committee: "If, through the introduction of a rigorous auditing process, we see anything like what we saw when that first happened some decade or so ago, it is quite conceivable that the police-recorded crime data could show an increase in the number of crimes recorded over the next little while...
"It is quite conceivable, indeed I think quite likely, that if there is proper auditing introduced, the recording of crime is improved, that we will see recorded crime increase."
Sir Andrew said there had been inadequate auditing of police crime figures since 2007-8, and statisticians had been voicing concerns about that for several years.
Those doubts had been heightened by the gap between the police data and the Crime Survey for England and Wales - which is still regarded as solid by UKSA.
But Sir Andrew admitted that a formal review of the statistics had not been launched until last June.
"Do I wish that we had been even swifter than that?" he said. "The answer is, honestly, yes. Given the concerns that we had repeatedly expressed about the lack of adequate audit and lack of progress on periodic and regular audit in the last three years, it would have, in my view, been good to have got to where we got to more quickly than we did."
John Flatley, head of crime statistics at the ONS, said some police officers appeared to be "confused" about whether offences should be recorded if there was not enough evidence to bring a charge.
Home Office minister Norman Baker accused UKSA of "jumping the gun" by de-designating the police crime figures before an investigation by HM Inspectorate of Constabulary (HMIC) had reported.
He blamed "human nature" and the Labour government for problems with the data.
Mr Baker said the Government had harboured concerns about the integrity of the information.
"But I was slightly surprised (by the UKSA action) in the sense that we have got the HMIC report exercise under way... we are due to have an interim report from them in April," he told the committee.
"I suppose I was surprised that they jumped the gun before that interim report was ready.
"But nevertheless there are clearly questions about the collection of the statistics.
"To that extent, I understand why they have taken the action that they have."
Mr Baker said he was "slightly more concerned" than he had been last month, when he insisted there was no "massaging" of crime figures going on.
"I still hold to the view that there is not an endemic problem in the sense that there is a deliberate attempt across forces to massage figures," he said.
Mr Baker said ministers had previously "recognised that there was a potential problem that we could not quantify".
He stressed that the coalition had acted to abolish national targets for crime figures in part because they appeared to be "driving behaviour".
The end of auditing after 2007/08 had also "sent a message" that recording of crime was not "as important as it had been", he added.
But Mr Baker suggested that human nature was at the root of some of the issues.
"It is, I think, human nature that people want to present their activities in the best possible light," he said.
"That may have led to skewing of figures.
"You won't change human nature, but what you can do, (is) perhaps put in place processes to discourage that from occurring by taking away incentives, and secondly making sure the scrutiny of data is of a quality that that is identified and stopped."
He said there was a difference between "innocent mis-reporting" and "under-reporting", branding the latter a "very serious matter" that chief constables should deal with.
Home Office Chief Scientific Adviser Professor Bernard Silverman said UKSA had set a "high bar".
"They have drawn a very high bar and then said that this statistic has not quite reached this bar," he said.
He stressed that the department's team dealing with crime figures was separate from the policy teams.
Mr Baker accepted that there was a "dent" in public confidence in the police data, but insisted that the crime survey was "pointing in the same direction" - to "crime being reduced".
"I don't accept that the Home Office has any interest in manipulating figures," he added. "We have no interest in having figures that do not tell us the truth."
But Labour MP Paul Flynn insisted they should be more "repentant" about the situation.
"You have clearly, both witnesses, got a remarkable capacity for self-delusion," he said.
Mr Flatley, of the ONS, indicated that the Crime Survey for England and Wales could be extended to provide data for each of the 43 police forces.
However, achieving a big enough sample size to give reliable results would add more than £13 million to the costs.