I checked on google and it seems that there are a lot of usages like the quoted but is this grammatically right?
accorded can take either an object or a prepositional phrase complement. It is a so-called di-transitive verb.
We accorded special treatment to them.
We accorded them special treatment.
them is the entity which benefits from the action, that is, the receiver or recipient or beneficiary of the benefit.
special treatment is the benefit, that which is (duly) given or accorded.
When those sentences are recast in the passive:
Special treatment was accorded to them by us.
Special treatment was accorded them by us.
Special treatment was accorded to them.
Special treatment was accorded them.
They were accorded special treatment by us.
They were accorded special treatment.