How do you get Health Certificates for Seafood to sell outside of the EU?

Question

Hello All

We are wholesalers of Frozen Seafood.
Our Customer has asked to produce health certificates for the products we are selling them, as they intend to export to Outside EU.
We did not import the goods and wish to hold the importers information which is visible on our suppliers health certificates.

Can we produce health certificates on our name and forward. If so, which GOV department we should approach.

Appreciate any help in this matter.

Reagrds