Compund particles 1 - ni matsuwaru, ni kakawaru

Expressions that represent subjects of a relationship - part 2

（１）彼はこの城にまつわる不思議な話をし始めた。
（２）彼は国連で軍縮にかかわる業務に従事しています

As forms which are followed by verbal predicates, they do not have te forms.
Ni matsuwaru is followed by (modifies) nouns such as talk, legend, rumor, anecdote, story and so marks things that are related to these talks, legends, rumors etc.
Ni matsuwaru can be replaced by ni tsuite no but ni matsuwaru implies an indirect relationship (between the story and the item concerned). Accordingly ni matsuwaru would not normally be used with "question" or "theory".

山田議員の環境問題｛Oについての/Xにまつわる｝質問は新聞でも大きく取り上げられた。

Although you can find ni matsuwaru as a verb in the dictionary it is never so used at the end of a sentence but always as a compound particle