The corporate regulator's permanent funding will be cut from $346 million to $320 million and staff numbers slashed by 30 investigators, in a unheralded budget cut described as shocking by insiders as the Hayne royal commission adds to the regulator's workload.

Tuesday's budget also includes cuts for the Office of the Director of Public Prosecutions - from $77.4 million to $73.75 million in two years - and for the Australian Federal Police from $1.03 billion to $926 million in four years.

Labor MP Matt Keogh said the cuts prove Treasurer Scott Morrison is "all bark and no bite" when it comes to fighting corporate crime. Mr Keogh said the cuts amounted to a 23 per cent reduction in staff at the DPP from 2010.

James Shipton ASIC chairman has discovered a surprise $26m budget cut.

Mr Keogh said the agency cuts were separate to and failed to offset $10.6 million provided to ASIC over two years and $2.7 million to the prudential regulator, which were loudly flagged in the budget to assist the Hayne royal commission. The budget also dedicated $6 million for cash economy prosecutions with no funding provided for any cases arising out of the royal commission.

The budget bombshell - discovered by The Australian Financial Review buried in the Treasury Department's accounts for the Australian Securities and Investments Commission, among a host of other obscure budget papers - is a slap in the face to newly installed chairman James Shipton who will see his war chest shrink by $26 million within three years and be forced to cut his staff by 30 by next year.