Can My Employer Sue Me For Leak Of Sensitive Information?

My employer forced me into resignation. The full & final settlement was done only after numerous reminders. I was also made to sign an affidavit stating that I won't leak the sensitive company information to competitive firms.
I have joined a competitive firm. The ex-employer has issued a legal notice putting charges of:
1. Extortion: that I threatened him on call, made illegal demands to pay me else suffer consequences.
2. Leakage of sensitive information to client.
For the charges he has no proofs as I never indulged into such activities.
He has threatened me into police and legal case unless I apologize. I shall not apologize as I never did such activities.
What should I do?

Hire an advocate and give a reply.
Do not get into any direct conversation/phone calls/letter writing to ex employer without a lawyer vetting the letter.
No one can prove a lie.
be calm but take prompt action to repudiate such allegations.
Keep your present company in the loop.
If you have not made any extortion call why is alleging something which cannot be proved.
Has ex employer specified what information you have allegedly leaked??
Why were you forced to resign?

Since you have already left the old organisation, he cannot charge you for professional misconduct (threatening and leaking of data) now under labour laws.
He can however, file a criminal case if he wants. However, how effective that will be is another issue.
As per Supreme Court, you cannot be stopped to join a competitive firm once you resign.
Since the ex-company has given you a letter with some serious charges which can put you in some trouble, reply the said letter through an advocate only immediately.
Check my blog at www.labourlawhub.com

@NathRao, the employer had mal intentions due to which he told me to immediately resign else he would terminate.
Allegations are for theft of their sensitive information, that too after 6 months of leaving the company. He has no proofs of allegations as I never did any. The reason of legal notice is that he is insecure that I had joined competitive firm