Who has the authority to "put away" someone from a church?

Does Matthew 18:20 teach that overseers put a person away from the assembly?

The parable of the straying sheep (verses 12-14) is an important part of the context of Matthew 18:20. The differences between this parable and the story of the lost sheep (Luke 15:4-7) are important. There the sheep is "lost"; here it has "gone astray." Here, the 99 are not in the wilderness, and the effort may prove to be a failure, as it was in the hypothetical case (verse 17). This is descriptive of the work of godly shepherds to recover a straying believer. Seeing recovery is shepherd work, there is good reason to consider the "two or three" of verses 16, 19 and 20 to be assembly elders or shepherds.

Elders act for an assembly in discipline cases, but their judgment is not arbitrary; it is in obedience to Heaven’s judgment. "Whatsoever ye shall bind on earth shall be (having been) bound in Heaven." The action of an assembly carries out God’s judgment. However, it is not merely elders who "put away"; it is an assembly action (1 Corinthians 5:13) with elders acting for it. Very often there are details of sin that should be only known and handled by elders. They have the confidence of the assembly and act tenderly as shepherds in behalf of the assembly.

N. Crawford