〜ともあろう
someone (of such standing) as
Noun (status) + ともあろう + 人 / 者 / 会社 + が
Sign up free to review this point on a spaced schedule.
ともあろう criticises someone for acting in a way unworthy of their position: 大臣ともあろう人が、そんな発言をするとは, "for a government minister, of all people, to make such a remark!".
The noun is a respected role: 大臣, 教師, 警察官, 医者, or a first-rate company. It's followed by 人, 者 or a similar noun, then が. The sentence usually ends with shock or disapproval: とは, なんて, 〜べきではない.
It's literally "someone who should be X", and you expect better from them. Compare ともなると, which just describes what's natural at a higher level.
Examples
大臣ともあろう人が、そんな発言をするとは。
For a government minister of all people to make such a remark!
教師ともあろう者が、生徒に手を上げるなんて。
For a teacher of all people to hit a student!
警察官ともあろう人が、交通ルールを守らないとは。
For a police officer of all people not to follow the traffic rules!
一流企業ともあろう会社が、こんなミスをするとは。
For a first-rate company like that to make such a mistake!
医者ともあろう人が、たばこを吸うなんて。
For a doctor, of all people, to smoke!