"Daar los mul tinvaak." would be the Dovahzul translation for that sentence. The reason "accusation" translates to "tinvaak" is because "tinvaak" represents not just speaking but arguments for dragons. 

If you want to be clearer, you can break apart "accuse" to mean "to make the person account for some crime/misdeed", then you can add something like "Daar los mul tinvaak do nahkriin." (talk/tinvaak of vengeance). Vengeance would likely be used if someone were accused.