He says there are too few safety inspectors under too much pressure and that they are working without adequate training or expertise.

Tim Cody left WorkCover, now WorkSafe, three years ago because his workload was affecting his health.

Mr Cody holds the distinction of leading the investigation that helped secure the ACT's highest fine against a company for work safety breaches when a concrete worker got his arm caught in an unsafe conveyer belt in Fyshwick in 2005. He wants the ACT government's response to the inquiry on four recent workplace deaths to give more power and funding to the regulator and he wants better-trained, better-paid inspectors on the job in greater numbers. The inquiry is due to report to the government next Friday.

Mr Cody helped secure a record $200,000 fine against Rocla Pipeline Products in August 2006, later reduced on appeal to $100,000.

He also led investigations into two workplace deaths: Nik Spasovski, who fell through an uncovered hole on the 11th floor of the Australian Taxation Office in Civic in 2006, and Geoffrey Gowan, who was crushed by a crane on the day of his 57th birthday in January 2009.

Mr Cody said his time at WorkCover had been busy and stressful, but he also felt he had made a contribution to helping keep Canberra workers safe.

He felt overwhelmed by his workload and took early retirement in 2009 but soon found himself in demand as a private safety consultant and now runs his own firm.

ACT Work Safety Commissioner Mark McCabe said one of the biggest problems he had in hiring experienced and qualified safety inspectors was that they could earn double the pay in the private sector.

In one of 20 formal submissions received by the ACT government inquiry - headed by the former Public Service commissioner Lynelle Briggs - Mr Cody said pay levels within inspector ranks were not competitive and should be both increased and broad-banded to provide a career path and promotions scale.

He believed the inspectorate had been ''worn down'' over the past decade by staff losses and budget cuts.

''The commissioner does a good job and the inspectors do the best they can under trying circumstances, but they don't have all the tools they need to do what they should be doing.''

The WorkSafe inspectorate has 34 staff but Mr Cody said that the number of inspectors policing safety on building sites on any given day could be as few as four.

And he questioned their level of expertise in dealing with specific construction issues.

Mr McCabe, the ACT Work Safety commissioner, said that the inspectorate had a range of duties including managing workers compensation and running safety education campaigns.

He had 18 dedicated inspectors working across work safety and dangerous substances, but conceded that up to half of those may work offline preparing prosecution matters, promoting safety campaigns or taking leave.

He also noted that while 60 per cent of inspections were undertaken in the construction industry, WorkSafe inspectors were also covering all other industries in the ACT including retail, health, community services and hospitality.

Mr Cody said the regulator was completely overstretched and had suffered ''a huge loss of corporate knowledge and experience'' in recent years and Canberra's building boom had made it even more difficult to fill positions.

He believed all inspectors should possess a minimum entry-level Certificate IV in Occupational Health and Safety, which was not currently the case, although inspectors were supported to earn the qualification while on the job, Mr McCabe said.

Another former senior inspector who was now working for a major construction company and did not wish to be named said he favoured the reinstatement of on-the-spot fines for lesser infringements.

Before an ACT government legislation change in 2009, which reduced the number of fines that could be imposed for work safety breaches, inspectors could issue an instant $5000 fine on a builder found not complying with safety regulations.

Now inspectors have to use the courts to prosecute cases, further increasing their workload.

The former inspector said: ''It used to be the case that the WorkCover inspectors were taken more seriously and feared to some extent. But now they have much less power or standing on a building site and I do think there must be a link in there somewhere to the fact that safety standards have fallen.''

Mr McCabe supported the view that fines ''can provide an immediate deterrent and can result in a very quick change in behaviour''.

''That doesn't mean we would not still use the court system to prosecute serious breaches,'' he said.

The former inspector said that given the huge amount of new construction work coming up in the ACT, a team of WorkSafe inspectors, experienced in construction, should be dedicated to policing residential, commercial and civil building sites across the territory.

''These are where the fatalities and serious injuries are occurring,'' he said.