2 docs get added for each new document ID added while replicating with Couchbase Elasticsearch plugin

In the administrative client for Elasticsearch the docs field should indicate the number of items that have been indexed by Elasticsearch.

But, when a new document is added to Couchabse server while the couchbase elasticsearch plugin is replicating 2 docs get added for each new document Id added in Couchbase server console.

For example, to start with the Couchbase server has 6 documents and 6 docs are replicated. But, while replicating if a new document ID is added the docs increase by 2.