Police described Douglas Lindsell as 'very dangerous and very organised'

His case comes as Parliament debates a new Sexual Offences Bill, which will introduce new offences and tougher penalties against sexual predators.

Lindsell, 64, from Twickenham, west London, contacted girls through chatrooms, passing himself off as a teenage boy.

He built up a database of more than 70 children, including details of hair and eye colour, clothes, schools, families and intimate details such as bra size and sexual likes and dislikes.

'Obsessive'

Lindsell corresponded with 54 girls in the UK and 19 abroad by obtaining e-mail addresses and mobile phone numbers.

Police said they were not aware of any other case where so many potential victims had been identified.

He even bought a book about teenage texting so he could sound more convincing.

He was obsessive in his pursuit of underage girls and continued to pursue them even after we confiscated his computer Detective Chief Inspector Chris Watts

He arranged to meet two of the girls, aged 13 and 14, but when they discovered how old he was they ran away.

Police say they came "within inches" of being assaulted.

Detective Chief Inspector Chris Watts described him as very dangerous and very organised: "Lindsell had a system of hunting, grooming and attracting young girls with a clear intention and that was to commit acts of indecent assault.

"He was obsessive in his pursuit of under-age girls and continued to pursue them even after we confiscated his computer."

Earlier this year Lindsell pleaded guilty to the attempted abduction of a girl under 14 and perverting the course of justice.

Indecent images

The latter charge related to Lindsell contacting victims and asking them to delete messages following his arrest.

Lindsell further pleaded guilty to gross indecency towards a female child under 16, making indecent images of children, and two counts of sexual and threatening harassment of a girl.

Eight indecent images were recovered from his computer.

The case echoes those of convicted paedophiles Michael Wheeler and Luke Sadowski.

Michael Wheeler also used the internet to groom under-age girls

Wheeler admitted 11 sex offences, including having sex with two 13-year-old girls after making contact with them through an internet chat room.

Detectives suspected he exploited current sentencing laws by waiting until the girls turned 13 before having sex with them, to avoid being jailed for life.

Sadowski was jailed for three years for trying to procure a nine-year-old girl over the internet.

The Sexual Offences Bill, which is expected to become law in the next few months, would give judges greater power when dealing with offenders like Lindsell, Wheeler and Sadowski.

A new offence of "grooming" will make it an offence to meet or arrange to meet a child with the intention of committing a sex offence, after at least two communications with them.

Paul Goggins, Parliamentary Under-Secretary of State at the Home Office, said: "The bill will bring in a series of measures to protect children and the most vulnerable.

"It will also introduce new offences with severe penalties against those who sexually exploit children, tightens up on the monitoring of sex offenders and, for the first time, terms sexual intercourse with children under 13 as rape."