I have a total loss in a Panamanian farming venture I invested in years ago. I never got any income and the company has gone belly up. How do I write off this?

In TurboTax (TT), enter at:
- Federal Taxes tab (Personal in  Home & Business)

 - Wages & Income

Scroll down to:

-Investment Income

   -Stocks, mutual funds, Bonds, Other

You will be asked if you got a form 1099-B. Whether you answer yes or no, the interview will allow you to continue.   Enter $0 as the sale amount and 12/31/22 as the sale date (since 2022 is the year you became aware the investment was worthless). 

the loss can be one of three types and we don't know which

1) a real investment loss. the investmnt was legit but never was profitable = capital loss

2) you were a victim of a crime there was no farming venture. in effect you money was stolem = no deduction

3) you were the victim of a Ponzi scheme. the loss is deuctible as a Ponzi theft loss but there are certain rules that must be followed to claim it - see form 4684 intrcutions for PONZI type loss.

https://www.irs.gov/pub/irs-pdf/i4684.pdf