Complex sentence: Lastly, a number of government bodies that are not police forces have detective powers and enforce laws, such as the Marine and Fisheries Agency and UK Border Agency, who employ officers with limited powers of detention and search but generally cannot make full arrests.
Split into simpler sentences: Lastly, a number of government bodies that are not police forces have detective powers and enforce laws. People employed by these bodies, such as the Marine and Fisheries Agency and UK Border Agency, enjoy limited powers of detention and search, but generally cannot make full arrests.