Do you know if schools usually contact referees (especially Bath)? One of my referee does not speak English and he asked me to translate the reference form for him. He also said I should put that they should not contact him for further info (or contact me first so I can arrange for the translation). I am afraid the admissions committee might think I am forging my references... but, at the same time, I fear they will contact the referee and he won't be able to comunicate with them...

You must not translate the reference. Discuss it with the school. If you translate the reference then both the referee and the translation are suspect. The school will obviously have staff or alumni who will speak the language.