Neo4j-admin memrec shows 0k for Lucene indexes

I have a database (Community 4.2.6) with a couple of full text indexes:

|94|stories|ONLINE|100.0|NONUNIQUE|FULLTEXT|NODE|[Story]|[title, body, country, date]|fulltext-1.0|
|72|storiesEng|ONLINE|100.0|NONUNIQUE|FULLTEXT|NODE|[Story]|[title, body, date]|fulltext-1.0|

The disk space used under /var/lib/neo4j/data/databases/neo4j/schema/index/fulltext-1.0 is 3.9GB, but when I run neo4j-admin memrec, I get:

# The numbers below have been derived based on your current databases located at: '/var/lib/neo4j/data/databases'.
# They can be used as an input into more detailed memory analysis.
# Total size of lucene indexes in all databases: 0k
# Total size of data and native indexes in all databases: 42000m

It seems the full text (lucene) indexes are not being found by neo4j-admin?