Who put them up for sell and why? If not the family how did they lose control of the medals?
I think it was the family that auctioned them off.
Most VCs are now eventually auctioned off - most families find they cannot afford the security needed to keep such a valuable artifact safe - there appears to be a significant market for stolen Victoria Crosses out there.
Export restrictions under Australian law would normally prevent a VC from being allowed to go overseas when sold. However something about the way this particular Victoria Cross was awarded meant that it didn't have that normal protection and there was a foreign collector interested, so there was concern that the Badcoe VC would be lost to Australia. Kerry Stokes has prevented that from happening.