A Brisbane law professor posing as pop singer Justin Bieber online to solicit explicit images from young children has been charged with multiple serious offences.

The 42-year-old man, understood to be in prison, was charged in November 2016 with a number of child sex offences including possessing child exploitation material and using a carriage service to groom persons under 16.

After a thorough examination of the man's computer, he has this week been further charged with another 931 child sex offences, including, rape, indecent treatment of children, making child exploitation material, using a carriage service to procure person under 16, and using a carriage service for child pornography material.

It will be alleged that the man used multiple online platforms including Facebook and Skype to communicate with his victims.

A large amount of child exploitation material was seized from his computer.

It is alleged his offending dates back to at least 2007.

Detective Inspector Jon Rouse said Task Force Argos, which investigates child sex crimes, would continue to target those using the internet to harm children.

"This investigation demonstrates both the vulnerability of children that are utilising social media and communication applications and the global reach and skill that child sex offenders have to groom and seduce victims," Detective Inspector Rouse said.

"The fact that so many children could believe that they were communicating with this particular celebrity highlights the need for a serious rethink about the way that we as a society educate our children about online safety.

"The breadth of offences committed in this instance are frankly horrendous and I want to recognise the efforts and commitment of the investigative team at Taskforce Argos to keeping children safe."

The man will appear in Brisbane Magistrates Court on April 6.