Queensland police have arrested a further 26 people in one of the largest child pornography investigations the state has ever seen.

The latest arrests, made in the last month, bring to 66 the number of Queenslanders nabbed under Operation Golf Cortex - the local arm of a national investigation.

Four teachers and five blue card holders were among those arrested on a total of 235 charges relating to the possession and distribution of child exploitation material.

Detective superintendent Peter Crawford, from Queensland's Child Safety and Sexual Crime group, said the material seized during the three month operation depicted the abuse and exploitation of babies as young as 12 months.

Operation Golf Cortex was launched in April following a mass swoop on users of a European-based internet site which featured child porn.

The international sting involved 170 countries.

"The operation once again highlights the effectiveness of law enforcement agencies working together to identify those who seek to abuse and exploit children," Queensland Police Commissioner Bob Atkinson said.

"Our officers have worked diligently and quickly, underscoring our absolute and unequivocal position of zero tolerance for those who access and download child exploitation material.

"It has been our first priority to target those people who may work with children and, as a result, four teachers and five blue card holders are among the 66 arrested in Queensland. Two of the teachers were charged by the AFP, and the remainder by QPS.

"In a prior statement we indicated there were six blue card holders. However, further investigation has established that there are actually five.

"Nevertheless, the variety of occupations of offenders charged during this operation illustrates the fact that offenders have come from all spectrums of society."