Database development/Data Mining/Webscrape to develop contact database/mailing list

I have a database of around 550 names and contact details from government agencies and government departments (specific agencies and specific departments) in Europe, which I require cleaned and verified (name, job title, organisation, postal address, and e-mail).
I then wish to increase the database to 1500 names (and full contact details including e-mail) of the same and similar types of organisations and people, again across Europe.