Comedian Drew Carey is offering a reward to help find the people who dumped a bucket of urine and faeces on a special-needs teenager.

The 14 year-old was told it was part of the Ice Bucket Challenge.

Carey says he'll donate $10,000 if police in Ohio, where the incident occurred want to start a reward fund.

The boy's mother found a cellphone video of teenagers dumping the bucket on her son who suffers from autism.