A warning was issued in August after police detected a batch of blue pills stamped with the super-hero logo and spiked with 25c-NBOMe, a synthetic LSD-like substance.

The Batman pills.

The pills had turned up in the southern region of NSW, on the state's ski fields and at a party in the Hawkesbury.

Police began a full-scale operation in May to trace the source of the pills and shut down the network of suppliers.