Police are monitoring social media for information about Friday afternoon's pack assault in the Scenic Reserve.
Several teenage boys were allegedly involved in the assault, which led to a Timaru man being admitted to hospital with facial and rib injuries.
The victim, 38, has since been discharged from hospital. He did not want his identity revealed, fearing repercussions.
However, the Herald has since been made aware of people allegedly involved in the assault boasting about it on Facebook.
Sergeant Ian Howard said police were aware of "some comments made on Facebook".
"We've seen them ... but our inquiries are still continuing. We've since spoken to about four or five teenagers who might have been involved in the assault."
The boys were aged 13 to 15. Mr Howard said it was likely they would be referred to Youth Aid once the inquiry was over.
NetSafe cyber security expert Chris Hails said people boasting about involvement in an assault would not constitute a legal confession and was not admissible as evidence.
However, police would be able to use the information for their own investigations.
"Whatever you put up there has the potential to be considered public information," Mr Hails said.
"We saw it last year with the ‘Roastbusters Scandal', where police looked at discussions taking place on Facebook about the alleged sexual assaults."
Mr Hails said there was also the risk of potentially "re-victimising" the injured party.
"Anyone who is concerned about cyberbullying should contact Facebook in the first instance, but we can also assist if necessary."
Mr Hails said the social media environment for cyberbullying had changed in the last year.
"Responding to concerns about cyberbullying on Facebook would have been about 20 per cent of our work about 18 months ago ...
"Many young people have switched to supposedly more ‘secret' social media sites, but there are always means of distributing information online."
People can report cyber incidents to theorb.org.nz or call for free help and advice on 0508 NetSafe (0508 638 723).
- The Timaru Herald