Crown prosecutor Evan McCaughan said the charges warranted an increase in Wales' prison sentence.
He also asked the court for an order to destroy Wales' computer.
There had been a dispute about the number of illegal images found on Wales' computer. The Crown said there were 500, of which 100 were more serious.
Wales told the court between 100 and 150 were illegal but he wanted to get the matter over and done with because he had been threatened in the cells.
Before today's hearing got underway, Wales' lawyer Chris Wilkinson-Smith opposed media applications to photograph and film his client because he was scared of what could happen to him in prison.
Judge McNaughton said he had received a letter from Wales to say that another prisoner - Glenn Holland - had been seriously beaten inside prison after stories about him appeared in the media.
Holland was sentenced at the Auckland District Court in March to three years in jail for being a party to sexual conduct with a child outside New Zealand and being in possession of objectionable images.
Wales is the first person convicted of organising a child sex tour overseas. He was found guilty by Justice Edwin Wylie in the High Court at Auckland last November after setting up a trip for a client, who was actually an undercover police officer.
The former real estate agent was also found not guilty of promoting the tour through a website.
The High Court trial heard how Wales told the undercover cop he could help him find Thai "boys'' as young as 13 to have sex with.
He booked flights and made hotel reservations for the trip before he was arrested.
The court heard Wales was initially reluctant to discuss sex with boys but later told the officer, who was wearing a wire: "I mean, the thing is, you know, like for instance, you could probably take a 13, 14-year-old boy back to a hotel, but not every hotel.''
Wales did not dispute creating the website, but his lawyer Chris Wilkinson-Smith said it was innocent and only for travel.
Mr Wilkinson-Smith said the undercover cop was his client's one and only customer in the three years the website had been operating.
In a police interview shortly before his arrest, Wales said: ''... firstly, he's offering me money to take him on the tour and I wanted the money. He's saying he wants something underage. I'm saying it's dangerous, but I wanted the money''.
Wales has previous child sex convictions in Australia.
