Turn it off, encase it in nanofabricated diamond, and bury it in a deep pit. Destroy the experimental records, retaining only enough information to help future, wiser generations to one day take up again the challenge of building a Friendly AI. Scatter the knowledge in fragments, hidden in durable artifacts, scatter even the knowledge of how to find the knowledge likewise, and arrange a secret brotherhood to pass down through the centuries the ultimate keys to the Book That Does Not Permit Itself To Be Read.

Tens of thousands of years later, when civilisation has (alas) fallen and risen several times over, a collect-all-the-plot-coupons fantasy novel takes place.

Want to restrain a man?

Use a facility designed by the government with multiple guards and built with vastly more resources than the imprisoned man can muster.

Want to restrain a machine?

You use the same strategy. Or you could use drugs, or build in a test harness. Whatever - but however you look at it, it doesn't seem like a problem.

We can restrain individuals pretty securely today - and there is no indication that future developments are going to change that.

What's with the question about removing restraints? That isn't a problem either. You are suggesting that the imprisoned agent contacts and manipulates humans "on the outside" - and they attempt a jail-break? That is a strategy available to other prisoners as well. It has a low success rate. Those few that do escape are typically hunted down and then imprisoned again.

If you are particularly paranoid about escaped prisoners, then build a higher security prison. Typically, you can have whatever security level you are prepared to pay for.