A former KPMG partner has joined widespread calls for a Royal Commission into the "Big Four" consultancies.

The global PwC tax leaks scandal has claimed its first government scalp with one of Australia’s most senior tax officials departing amid revelations by The Klaxon.

One of Australia’s most senior tax officials worked directly at PwC with at least two of the partners named in the consultancy giant’s tax leaks scandal.

Referrals to the Federal Government's new anti-corruption body have exploded more than four-fold in its first two days of operations.

The names of more than 50 PwC partners and staff who received or shared confidential Federal Government data in the tax leaks affair remain hidden.

The 100 per cent owner of Australian telco giant Optus, the Singapore Government-controlled Singtel, states it has “zero tolerance” for “bribery and corruption in any form”.