The pair exchanged emails, phone calls and text messages and met four times to discuss the details.
The officer was wearing a covert recording device. Several of the conversations recorded were played to the court yesterday.
At first wary of "Michael Grey", the man discussed tourist attractions and things to do in and around Thailand.
The officer then said he hoped to find "a young friend" on his travels and was attracted to pre-pubescent boys.
"How young? Don't worry I don't mind," the man told the officer. "I don't have any moral issue with it."
He told the officer he did not completely trust him and was "not 100 per cent happy talking about it".
"I don't know whether you're wearing a wire or you're from the police ... or from a TV station or who knows," he said.
In the recordings, the man then spoke to the officer about the dangers and legal issues involved with underage sex and said he would not help him with that directly. But he agreed to organise a trip and said he would accompany the officer to show him the ropes and keep him safe.
Ms Walker, in her opening address, said they discussed sex in Thailand "at length".
The man allegedly spoke of picking up a 14-year-old and travelling to a town in northeast Thailand where he "had a few" of the local boys.
The trip was booked and the man was arrested soon after and charged with organising the tour and operating and maintaining an objectionable website.
She said the man's website did not have any direct reference to sex, but intimated it through "suggestive" language.
Meta data, or coded words to help search engines locate and offer the website when people search for particular words, found on the website included: gay, gay sex, Thailand, boys, get together and tour.
"There can be no dispute that the aim of the tours was to have sex with underage boys by paying for it," Ms Walker said.
"This is a man who is sexually attracted to boys and has no moral problem having sex with Thai boys."
The man's lawyer Chris Wilkinson-Smith said in his own opening address that his client did not dispute creating the website - but it was innocent and purely for travel.
He said the officer was the man's one and only customer in the three years the website had been operating.
"He candidly accepted that yes, he has an attraction to teenage boys. But he is very aware ... of how much care he needed to take not to cross the line," Mr Wilkinson-Smith said.
He said his client used the word "boy" loosely when discussing his sexual experiences and did not mean underage males when using it.
"It can encompass underage boys or be a reference to people aged 18 plus, particularly in a Thai context.
"Referring to a boy in gay culture denotes a social status, rather than a biological age."
The trial continues today.
