Risks involved in writing a biography of a martyr.

If it pertain to a individual then need to get their consent by writing is must. without  their permission if any one write unwanted things then they are liable to answer before law and face all consequences.

Hey, 

If the biography makes references to the government departments in any manner which are critical, then it is advisable to take permission from them before publication and after completion of the biography, to avoid any future issues. Otherwise, without taking permission if you publish and they sue you for defamation, you would have to contest the same in a court of law.