Is Robert Mueller running a legitimate investigation into allegations of collusion between the Trump campaign or officials in it and Russia?

Robert Mueller hasn’t decided whether to actually investigate Trump: Report

Special counsel is investigating Trump for possible obstruction of justice, officials say

Mueller Seeks to Talk to Intelligence Officials, Hinting at Inquiry of Trump

Special counsel is investigating Jared Kushner’s business dealings

It isn’t possible for the Mueller investigation to be legitimate with all of these leaks about his investigation and its status and findings that he’s permitting to occur.  Or that, Comey-esque, he’s doing himself.

He’s plainly not investigating his leaks, else that would have been leaked, too.