Singtel says a second of its Australian companies has suffered a serious data breach, compromising sensitive details of up to 20 clients and 1000 workers, the month after Optus suffered one of the largest in Australian history.

The breach at IT services consultancy Dialog, bought by Singtel in 2020, will raise the pressure on the Singaporean tech giant as it weathers criticism of its governance and cybersecurity practices after Optus lost personal details pertaining to nearly 9.8 million current and former customers in September.