The National-led Government has come under renewed pressure over its approach to mine safety before the Pike River disaster.
Twenty-nine men died in a series of explosions that began at the West Coast mine on 19 November last year.
Labour Minister Kate Wilkinson faced a series of questions from Green and Labour MPs in Parliament on Thursday about what mine safety concerns had been raised with her since 2008.
The West Coast-based Green Party list MP, Kevin Hague, asked Ms Wilkinson whether she agreed with submissions made to a Department of Labour inquiry in 2008 which raised serious questions about the state of mine safety.
Ms Wilkinson said she did act on some of that inquiry's recommendations.
However, the minister says in relation to Pike River, the Royal Commission is still to determine whether the disaster was a consequence of operational and/or regulatory failure.