Resignation from directorship - What should I do to protect myself from any legal and financial irregularities?

I worked with a startup as director with 25% shares and also as an all round sales cum operations person since 2014 to 2018 and resigned from the organisation as an active member in january 2018. Although I stopped working and moved on with family business, I didn't formally resign from the post due to certain bank liabilities. Its been almost 18months and now I feel certain irregularities might be happening and I should have resigned formally.
What should I do to protect myself from any legal and financial irregularities that might have happened in my absence.
Thanks in advance

Hi,
You can detail the background of your illness in the resignation and request for relief predated. Board has to approve and in your relieving date should be pre date the date when you have actually left. Thus they can't hold you responsible for the irregularities took place in your absence.

Thanks V. M.
Should I talk to the directors in advance or should I straight away mail them my resignation letter.

Hi,
Ofcourse, first discuss and then proceed with resignation.
In your email/resignation communication high light your actual period of absence indirectly ( I regret for my non participation due to my illness....) and this can act as proof in future in case of any dispute in future.