I also found this example in the Cambridge online dictionary: "The police suspect him of carrying out two bomb attacks." Do you think this example is an exception to the rule?
You are right. That example works. I have to say that the perfect form of the nonfinite works better to refer to the past with stative verbs and when there are no details pointing to a specific occurrence. Please compare:
1. The police suspect him of being a terrorist.
2. The police suspect him of preparing bomb attacks.
3. The police suspect him of carrying out two bomb attacks.
In (1), "being" is stative and that sentence will most likely be interpreted as: The police suspect he is a terrorist (not was).
In (2), "bomb attacks" is unspecified and, as a result, that sentence will tend to be interpreted as: The police suspect he is involved in the preparation of bomb attacks.
In (3), the present-past ambiguity is dispelled by the presence of a specific detail pointing to the past, along with the meaning of the verb "carry out."
Instead, the sentences:
- The criminal is suspected of being aided by other individuals.
- The criminal is suspected to be aided by other invididuals.
are at best ambiguous as to the time of the aiding. To me, in the absence of further information, they sound as if they are suspected of having (not "having had") accomplices.