Odious debt is more of a literature than a doctrine. Going back to at least the 1920s, one can find arguments that countries should not have to pay back debts that are labeled "odious." The central intuition is that the citizens of a country should not have to pay for the debts incurred by a prior "odious" regime when those funds did not benefit these citizens. It is simply not right to ask people to pay for funds from which they did not benefit, especially when the lender knew of this fact when it made its loan. Here, Rasmussen comments on the guiding inuition on a past odious debt that may lead to an overall debt relief.
Robert K. Rasmussen,
Sovereign Debt Restructuring, Odious Debt, and the Politics of Debt Relief,
70 Law and Contemporary Problems
Available at: https://scholarship.law.duke.edu/lcp/vol70/iss4/10