Called, no voicemail left. I've also suddenly started getting calls from a group of mobile numbers apparently used by Iselect to spam-call, so this could be related.

I think its in relation to iselect ... was comparing health insurances.

I believe the call is from iSelect. I was comparing prices and at first I received 2 calls from a mobile. I called one back to get the iSelect message. They then tried from this number but again I did not answer.

Called, no voicemail left. I've also suddenly started getting calls from a group of mobile numbers

Also got a call from this number randomly, possibly scammers.

Got this call after looking at a couple of sites that compare health insurance

I called back number (03) 9007 7002 reached voice mail but did not say for what company.