Disturbing footage has emerged of two teens hurling a 12-year-old boy into a freezing lake.

Police are now investigating the alleged incident that occurred at Forest Lake Amphitheatre, located within The Lake Parklands in Brisbane's south on Thursday.

The video, which was initially posted on TikTok, showed two teens in school uniform and backpacks picking up the smaller boy and dangling him in the air at the pier.

'Chill, come on', you are actually f***ing dragging me,' he pleaded.

'Chill bro, I can't swim.'

Another boy watching on was overheard saying, 'just send him bro'. 

Laughter was heard as the fully-clothed boy was thrown into the water.

The lake is prone to blue-green algae outbreaks, which are dangerous to wildlife and humans.

Queensland Police confirmed it is investigating the incident. 

'Officers are aware of social media video of the incident and are currently in contact with all boys involved and their families,' the spokesman told Daily Mail.

No charges have yet been laid. 

The alleged bullying incident shocked not only the community but also Queensland Police Minister Dan Purdie.

'We don't tolerate any kind of physical assault,' he told reporters on Friday.

The young boy's sister shared a desperate plea to those involved.

'I hope you get a good wake-up call that being a bully isn't the right answer … so please be respectful of others and be kind, because one day you will become a parent yourself and understand how much we sacrifice to keep you safe each day,' she posted online.

The mother of one of the boys allegedly involved has since apologised to the victim and his family through an anonymous post on a community Facebook page.

'As a parent, my heart breaks knowing that my child has caused another child fear, distress and trauma,' she wrote.

'No parent ever wants to see their child hurt, and I am deeply sorry that your son experienced this because of my son's actions.

'I know that an apology does not erase what happened, and I don't expect forgiveness.

'My hope is simply that, over time, my son learns from this, takes responsibility, and becomes a better person because of it.'

She added that her son has since taken accountability for his actions and spoke with police late Thursday night.

He has also been suspended by his school. 

'Our family is not ignoring what happened. We are taking it very seriously,' his mother added.

'My son is facing consequences at home, and we are fully prepared for any further consequences that come through the school or the legal process.

'Accountability is important, and we are not trying to avoid it.'

The Department of Education is also investigating. 

 'Any student who is determined to be involved will face appropriate consequences,' a spokesman said.