The head of Australia’s union movement has renewed her attack on construction company Grocon, accusing the company of being reckless and suggesting that penalties levied against the company were unfair and insignificant compared with those imposed on the Construction, Forestry, Mining and Energy Union (CFMEU) over its dispute with the company.

Issuing a clarification of sorts to an earlier statement in which she had accused the company of ‘killing five workers’, newly elected Australian Council of Trade Union Secretary Sally McManus said there was a disparity between the $250,000 fine levied against Grocon over the collapse of a wall which killed three passers-by and the $4 million which she says has been levied against the CFMEU over the course of its dispute with the company.

“While it was not accurate to say ‘Grocon was fined $300,000 for killing five workers,’ it is accurate to point out that the huge discrepancy in fines paid by the company and the CFMEU is a glaring example of the inherent unfairness in our industrial relations laws,” McManus said in her statement.

McManus’s clarification follows an interview she gave on the ABC’s 730 program in which she argued that fines and penalties levied against the CFMEU throughout its dispute with Grocon were disproportionate when compared with the punishment received by the company over safety breaches.

“So Grocon got fined $330,000 for killing five workers, where the CFMEU got fined even more. And I just think that’s totally wrong,” she told the program.

The company hit back, describing the statement as ‘manifestly untrue’ and writing to McManus seeking correction.

Whilst not denying that fatalities had occurred its sites, Grocon said there had never been a finding that the company had caused any deaths.

The latest spat refers to two incidents which occurred on Grocon sites in early 2014.

In one incident in February that year, 59-year-old crane driver Bill Ramsay fell about ten stories to his death early on a Monday morning.

The following month, three by-standers including a brother and a sister were killed whilst walking along Swanson Street after a large brick wall collapsed in strong winds.

In 2014, the company was fined $250,000 over safety failures with regard to the Swanson Street incident after it pleaded guilty to fault in assessing risk but not to causing the deaths.

A Coroner investigation found there were no safety issues involved in Ramsey’s earlier death.

McManus says this was inadequate.

“Following the Swanston Street incident, Grocon pleaded guilty in the Magistrates Court to a single breach of the workplace safety law, was convicted, and ordered to pay a fine of $250,000 – less than a quarter of the maximum available penalty,” she said.

“This compares with the almost $4 million in fines levied on the CFMEU over a similar timeframe for protesting Grocon’s record and taking action to stand up for worker safety on construction sites.”

The latest controversy follows earlier comments in which McManus appeared to condone unlawful activity where laws were considered to be unjust.

Those comments drew fire from industry lobby groups, who accuse the ACTU boss of encouraging lawless behaviour and argue that any changes to laws should be pursued through democratic means.