Apache Lucene.Net 2.4.0 Class Library API

IndexReader.DeleteDocument Method 

Deletes the document numbered

docNum
. Once a document is deleted it will not appear in TermDocs or TermPostitions enumerations. Attempts to read its field with the {@link #document} method will result in an error. The presence of this document may still be reflected in the {@link #docFreq} statistic, though this will be corrected eventually as the index is further modified.

public void DeleteDocument(
   int docNum
);

See Also

IndexReader Class | Lucene.Net.Index Namespace