Using private APNIC range in US

Hi all, I have a client here in the US, that I just discovered is using a host of private IPs that (as I understand) belong to APNIC (i.e. 1.7.154.70, 1.7.154.00-99, etc.) for their web servers. I'm assuming that the addresses probably nat to a [US] public IP. I'm not familiar enough with the use of private address space outside of ARIN (i.e. 192.0.0.0, 10.0.0.0, etc) but I figure if their sites are up and accessible it must be working for them. I'm just wondering if there is any recommendation or practice around this -- using private IP ranges from another country. Thanks. --Jaren