WordPress is generating sub pages i.e. /page/id/ for all pages on site

Hi!

Since some days, we noticed in Google Webmaster Tools as well as in Google Search Engine that WordPress has generated invalid pages for all our WordPress Pages. We’ve added around 8 Pages on our site. The urls are looking like:

http://www.example.com/privacy-policy/page/75/
http://www.example.com/privacy-policy/page/109/
http://www.example.com/privacy-policy/page/110/
http://www.example.com/privacy-policy/page/111/
etc. many urls with no.
http://www.example.com/contact-us/page/6/
http://www.example.com/contact-us/page/108/
http://www.example.com/contact-us/page/111/
http://www.example.com/contact-us/page/68/
&

As well as Canonical URLs are also same with these URLs.
So on with every 8 pages that subpages are present. When we click on that page that page opens original pages i.e. http://www.example.com/privacy-policy/ and http://www.example.com/contact-us/ but URL in browser address and in Canonical remains the same as spammy urls like http://www.example.com/privacy-policy/page/75/ and http://www.example.com/contact-us/page/6/.

This is the issue with only Pages yet not with Posts. Why our WordPress has generated these sub-pages which really doesn’t exist? We’ve tried disabling plugins and updating permalinks, but No luck. Please help what can be the issue and how to resolve this issue? Please Help. Thanks in Advance.