The Morrison government's industrial relations omnibus bill will include a strengthened compliance regime after years of underpayment scandals.

Industrial Relations Minister Christian Porter said it would be the first time a commonwealth wage theft law exists.

He said last week's revelations that some blueberry workers were paid as little as $3 an hour on NSW farms showed why the government was acting.

"It shouldn't happen. It's disgraceful," Mr Porter said.

The new offence will carry a maximum penalty of four years' jail and fines of up to $1.1 million for individuals and $5.5 million for companies.

It will apply to national system employers that deliberately underpay one or more workers.

People convicted of wage theft would be disqualified from managing companies for five years.

The offence will not apply to one-off underpayments, inadvertent mistakes or miscalculations.

Aside from a new criminal offence, the government will also introduce a new type of civil penalty linking fines to the amount of underpayment.

Mr Porter said a "benefit gained" principle would be applied to effectively allow employers to be fined the higher of two or three times the amount not paid to employees or the maximum fine.

Increased business fines will range from almost $20,000 to $666,600 depending on the size of the company.

Australian Industry Group chief executive Innes Willox is against criminal penalties for wage underpayments.

"If the government's bill includes such penalties, it is important that the provisions are fair and balanced," he said.

"The offences should only apply to deliberate, dishonest and serious conduct."

Wage scandals have engulfed the hospitality and retail sectors in recent years, with high-profile cases including celebrity chef George Calombaris, 7-Eleven and Woolworths.

Horticulture has also come under fire as farmers seek more labour amid ongoing exploitation concerns.

Australian Associated Press