A 49-year-old Timaru man has been jailed for four years and nine months for his involvement in the online sexual exploitation of children

He was searched at Christchurch Airport last August when returning from an overseas holiday.

Customs officers found more than 300 child sexual abuse files on his phone - and forensic analysis found he had distributed files while on holiday.

A later search of his home found a hard drive with more than 170-thousand files - including 33 hours of video of the worst category of material.