Question: Can a CA suspend the digital signature certificate issued by it?

Ans: See  Dr. Zulfiquar Ahmed, A Text Book on Cyber Law in Bangladesh, (Dhaka: National Law Book, 2009), pp. 108-109.
And read more, the following suggested readings are enlisted here:

1. ABOUT THE SITE
2. cpsch13
3. Cyber Crime, Cyber Law, Cyber pornography
4. RCMP Certificate Services Program – Glossary
5. Thawte is a leading global SSL certificate authority of SSL …
6. New Page 1
7. Internet Law and Policy Forum – Working Groups and Publications
8. Method for determining whether past digital signatures were issued …
9. GENERAL PROVISIONS
10. Annexure