• What kind of legal remedies are there for this breach of trust

I run one NGO.  In the year 2007 a married lady joined me as my Assistant in this NGO Office. Initially it was usual official relationship but after 6 months, she started seducing me.  She became very possessive to such an extent that even if my wife talks to me she will not like it.  She was very good at work and I was ignoring initially the passes but later on I also fell for her and we both got illegally married at a temple outside the city and only we two were aware of that marriage and no one in the society knew about it.  The relationship carried on for some years until my legally wedded wife came to know.  

My wife took corrective action in ensuring she moves away from me and I cooperated with my wife and that lady also cooperated to stay away.  Since knowingly or unknowingly we got into extra marital affairs, I invested on opening a new NGO in her name and I invested all the money, where she and her husband are the Trustees and I took no role in the NGO other than helping them financially from outside as a well-wisher to their family.   I set up an office for them by paying advance, invested on office furniture and also financially supported them for some time.  The idea of opening this office for her was to give her a livelihood throughout her life and it was done with a good intention.  

This happened in Jan 2016 and without the knowledge of my wife.   Again, my wife came to know about this after some months and again she ensured that we both talk to each other and disconnect our association.  That lady was not willing but this time, I was stubborn in my decision and I said 'no more such connection' and did not yield to her pressure.   I decided to disconnect with her permanently this time and since I have given her livelihood, I did not feel the guilt of disconnecting. 

When she came to know I am very stubborn this time, she has started creating problems for me.  She has started demanding money and she is likely to demand a big ransom from me and I am anticipating more trouble. 

All my office documents are with her in that office and she is now not cooperating to give all that.  She is also threatening me that all my present donors will be informed about the dis-association of my NGO and her NGO.  If she does this, it will affect our NGO's credibility and since she knows this, she is now black mailing me that if I don't accede to her demands, she will spoil the NGO's image in this manner.  In the bargain, her NGO image will also go and something tells me she will not jeopardise her NGO image also in this. 

I would like to take legal help and lock her office since I was the one who has paid the advance for the premises and through my financial support only she was able to run the NGO.  Once I take back all the documents related to my office, I will not have any problems since she will not have data to do any damage for my NGO.  I will let her run her NGO independently thereafter. 

Our illegal relationship is not known to her husband or her family or her relatives but I know some of them. I also have a point to threaten her.  But I would rather proceed taking legal steps in protecting myself and my office documents rather than yielding to that kind of tactics.  

I am not justifying my actions but having realized that I made a mistake, I am trying to correct myself but she is blackmailing me and not allowing me to lead a peaceful life. 

I need expert advise from you all how to tackle this issue tactfully.  Is there any legal remedy for this.