Australian Conservatives senator Cory Bernardi has described Muslim halal certifiers as 'cockroaches' who are running an extortion racket on the nation's food suppliers.

The 48-year-old Liberal Party defector has stepped up his campaign to regulate the industry as more than 500 workers at Sydney's Red Lea Chickens are without work, following the company's decision last year to stop serving pork-based bacon.

The Adelaide-based senator has accused the Islamic halal certification industry, which charges food producers fees to declare their goods contain no pork or alcohol, of lacking transparency.

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Australian Conservatives senator Cory Bernardi has described Muslim halal certifiers as 'cockroaches' who are running an extortion racket on the nation's food suppliers

He compared them unfavourably with Jewish kosher certifiers, claiming Muslim halal businesses were evasive with a Senate inquiry he was part of in 2016.

'The halal certifiers, they ran like cockroaches under the fridge when the light comes on,' he told Sydney radio 2GB broadcaster Alan Jones on Monday.

Senator Bernardi, who plans to introduce a new private member's bill in May to regulate the industry, said the Senate inquiry had failed to even identify 'who the domestic certifiers were'.

The senator has stepped up his campaign to regulate the industry as more than 500 workers at Sydney's Red Lea Chickens are without work, after it took pork-based bacon off the menu

He told Alan Jones (pictured) the Islamic halal certification industry, which charges food producers fees to declare their goods contain no pork or alcohol, lacked transparency

'There's no transparency, there's no accountability and the only conclusion I could draw is that the domestic halal certification is a racket and a scam,' he said.

Senator Bernardi criticised the halal industry for charging businesses a fee to fund Islamic activities, like schools and mosques.

'It's an extortion basically on companies to say, "Unless you pay us a fee ... we're going to claim you're racist, we're going to tell the Islamic community that you're a bad bunch of people to go business with",' he claimed.

However, Halal Certification Authority president Mohamed Elmouelhy has argued halal certification had helped Australian businesses gain export contracts in Indonesia, the world's largest Muslim-majority nation, where halal certification will be compulsory on food from October 2019.

The Australian Federation of Islamic Councils receives a halal certification fee from Vegemite's parent company Bega and funds the Malek Fahd Islamic Schools in Sydney's west

In October, Red Lea sent out a letter to its franchisees and wholesalers telling them pork products would be taken off the production line

The Australian Federation of Islamic Councils receives a halal certification fee from Vegemite's parent company Bega and has used its cash reserves to fund the Malek Fahd Islamic Schools in Sydney's west.

In October, Red Lea sent out a letter to its franchisees and wholesalers telling them pork products would be taken off the production line.

This heralded an end to bacon-wrapped chicken mignon and bacon twists, with bacon-flavoured chicken used instead of cured pork.

Its workers received notices at Easter informing them the company had been placed into receivership.

Senator Bernardi's Australian Conservatives has recruited Halal Choices founder Kirralie Smith, a northern New South Wales farmer, who has been campaigning for transparency in the halal certification industry.