Originally posted here by mark_boyle2002
Can anyone think of or does any one know any way to do the same ?
I think you want to do an inverse query. You should be able to do a whois -i ac AB1234-RIPE to lookup all domains that have the admin contact AB1234-RIPE.

You can find more info here

Edit: I tried to do a whois -h whois.ripe.net -i ac AB1234-RIPE on a FreeBSD machine but it gave me all sorts of errors. Doing the search on the ripe website however did work.