The police investigation into a text message allegedly sent from the cellphone of National's Sarah Dowie is continuing but neither the MP nor her party will say whether she is speaking to police.

It's a high-risk game, says Victoria University of Wellington political scientist Dr Bryce Edwards, because the public was likely to expect any MP to co-operate with police requests for assistance in investigations - and to tell voters they were doing so.

Edwards said it was likely Dowie's days as an MP were numbered after finding herself enmeshed with Ross and his catastrophic exit from the National Party.