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Police are carrying out a new study on the usefulness of lie detector tests.
The Association of Chief Police Officers (Acpo) said the research was being led by Hertfordshire Constabulary.
The force is reported to have completed a successful pilot scheme in November in which 25 "low level" sex offenders were tested.
Many were exposed as being a higher risk to children than originally thought, The Times reported, and a further 12-month trial has been approved to begin in April.
An Acpo spokesman said today: "We monitor any new approaches or technology which could provide a positive benefit in helping investigate crime, support victims and put offenders before the courts.
"The Acpo Homicide Working Group provides advice to the police service on the use of polygraph techniques and will follow with interest the latest study led by Hertfordshire Constabulary.
"Polygraph techniques are complex and are by no means a single solution to solving crimes, potentially offering in certain circumstances an additional tool to structured interrogation.
"These initial trials are in their very early stages and we will follow their progress, working with chief officers across the country to provide further guidance if necessary.
"Whether these techniques are adopted elsewhere in the country is a matter for individual Chief Constables."
The newspaper said the tests were being used to help decide whether to charge suspected criminals for the first time in British policing history.
Although Devon and Cornwall Police had used a lie detector on a single occasion when investigating a violent crime, the Hertfordshire trial was the first use of pre-conviction testing in the UK, it said.
Offenders can only take the tests if they volunteer, and evidence gained is not admissible in court, it added.
Of the 10 offenders tested in April, six revealed more serious offending and testing ended so further inquiries could take place.
Of the other four, two revealed offences, thus passing the test, and received cautions and attended a sexual offender treatment programme.
The last two made disclosures and passed the test but refused to admit the offences when interviewed later. Their cases went to court. All four were placed on the sex offenders register, the newspaper said.
Of the 15 offenders tested in November, eight failed while six passed. One was caught trying to beat the polygraph, breathing erratically and talking slowly.
Detective Chief Inspector Glen Channer, head of the the force's child protection unit, said the polygraph was an "added weapon in our armoury of investigative techniques".
He said the tests were carried out by accredited practitioners in a scientific environment and were not relied upon on their own.
Hertfordshire Police said in a statement today: "The use of polygraph (lie detector) testing to speed up the risk assessment process on 'low level' sex offenders has been trialled by Hertfordshire Constabulary.
"The testing is undertaken ahead of any charges being brought and involves specialist officers from the constabulary's paedophile unit working with an expert who conducts the test on first-time offenders who have volunteered to co-operate with police. Evidence elicited during the examinations is not admissible at court."
Mr Channer, who heads the constabulary's public protection unit, said: "The polygraph testing provides us with an additional tool and has cut down investigative time significantly, leading to a more efficient process, often helping to identify additional offences."
The integrity of the process was paramount, he said.
The statement said that 25 "low level" sex offenders participated in the first trial, and a further 12-month trial is expected to start in April.
PA