indexed sub domain removal

i have a sub domain multi site with domain mapping being used.

I checked google to see how many indexed pages i have and sub domains are coming up. i.e.

client.mydomain.com
client1.mydomain.com

Client and client 1 are mapped to client.com and client1.com

client.com is being indexed correctly but it is also being indexed as client.mydomain.com

how do i get rid of the sub domains on my main site on google?