There is concern the Government's probe into controversial private investigation firm Thompson & Clark doesn't go far enough.

An initial investigation was launched earlier this year after it was revealed government-owned insurer Southern Response hired the firm to spy on earthquake claimants.

But it has now been expanded after revelations the company has left tracks through other arms of government including the SIS and MPI.

Activist Valerie Morse has filed OIA requests on it and told Kate Hawkesby the investigation isn't wide enough, despite SIS director Rebecca Kitteridge promising to look at it.

Morse says she isn't sure if the State Services investigation is going to be wide enough and would like to see Parliament have a look at this matter.

"I think that there is at least some suggestion that the relationship is much deeper between the SIS and Thompson & Clark."

Commissioner Peter Hughes has widened the inquiry to include all government agencies.

Morse says a number of Government departments are implicated and she wants the State Services Commission to also take public evidence in its probe.

"In terms of Southern Response, like these are ordinary New Zealanders who survived the Christchurch earthquake who are seeking they're lawful entitlements and they're being spied on."

LISTEN ABOVE AS VALERIE MORSE SPEAKS WITH KATE HAWKESBY