Complicative Situation

Hi This is Shaan,,I love my girlfriend very much,her name is Mousumi sarkar,she also loves me so much.Before being my girlfriend she had a boyfriend,but that guy does not loves her he only loves her property,because her father is a very richest person.Now after know this matter she has reject him,but now that guy & his mother are blackmailing her that if she will not marry him then he will do suicide by writing a suicide note against her & his mother is continously forcing her to marry him or else his mother will go to the police station & complain against her that due to that girl her son has done suicide.His mother also threating her that they have a photo of her & by that photo they will go to visit her father & forcing him to his daughter to them......
Due to this matter my girlfriend is become very tensed & I am also in tension for my girlfriend.I am staying now out of India due to my job.I have talked already with my would be Mother-in-law.She is giving me support very much.But my girlfriend is in very much tension.
So, all of you are kindly requested to suggest me regarding this matter.Awaiting for your friendly help.