Environment Minister Greg Hunt has released the final update on the government's response to the program, which ran from 2009 to 2010.

Mr Hunt said payments to pre-existing insulation installation businesses adversely affected by the program would be completed by April.

The government last year confirmed compensation had been paid to the families of four men killed under the program – Matthew Fuller, Rueben Barnes, Mitchell Sweeney and Marcus Wilson.

Mr Hunt said in the update that bureaucrats behind the scheme would not be formally investigated, however new checks and balances within the public service had been put in place.

A review by Australian Public Service Commissioner John Lloyd completed in March last year concluded that there was “not a sufficient basis for formal investigations of individual public servants to proceed”.

The minister said work in other areas such as improving safety in roof spaces and ensuring all federal government programs minimise work health and safety was continuing.