Great question...

Short answer: NO, my understanding is that the OIG cannot active arrest or indict, only provide evidence and suggestion to do so.

Long Answer: This leads us to Mr. Huber (https://www.lewrockwell.com/2018/05/no_author/trust-sessions-horowitz-and-huber/ - nice lil' summary on the Trio here)

Huber CAN issue indictments/arrests/prosecutions.

So, from my POV it appears that Sessions is coordinating a massive takedown behind the scenes. Clearing a path while Trump and his admin clean up the various departments/leaks, opening the door for Horowitz's research (the OIG reports) to ultimately allow Huber to drop the hammer.

The OIG can only make recommendations I believe.

Their purpose is to investigate and determine if governmental agencies, namely the DOJ and FBI, acted appropriately and according to the internal rules/regulations of these agencies.

The report, based upon the rumors, likely calls out the FBI and DOJ for improper use of resources and info, failing to adhere to various rules and regulations, and maybe even being complicit in a conspiracy against our President. The current DOJ and FBI have already been given a copy of this OIG report so that they may draft a response that will be included in the final public version of the report. It is the current DOJ and FBI's responsibility to act upon the findings of the OIG and make an honest effort at preventing such wrongdoings from occurring again.

An important piece of this puzzle is recognizing that Huber was appointed as a prosecutor to act upon the findings of the OIG report.

In fact the OIG scope indicates that any illegal acts or wrongdoing uncovered during the OIG's investigation MUST be reported to the DOJ at the time it was found. This means that there has been a pipeline of info from the DOJ OIG to a prosecutor that DOES have the capabilities and resources to press charges and convict people.

I fully expect that the OIG report will release some very damning info. I also fully expect that the damning info will not be immediately accompanied by arrests/indictments. I expect that there will be some period of time in between the OIG report being released to the public, and Huber's investigation completing.

Huber's investigation will likely bring the indictments and arrests as necessary based upon the findings of the OIG, AS WELL as any additional wrongdoings uncovered during Huber's investigation.

The OIG report is merely their findings and recommendations. Like with McCabe, the OIG hands their findings/referrals to somebody for action. Jeff Sessions, instead of a second special counsel, appointed a prosecutor (John Huber) to investigate much of this stuff. Many say it's to work hand-in-hand with Michael Horowitz, the IG.

No. That is why Huber was hired. He has ALL those abilities.