SAN FRANCISCO (Reuters) - Neo4j Inc, a graph database firm whose technology was used in investigating the “Panama Papers,” said on Thursday it closed an $80 million Series E funding round led by One Peak Partners and Morgan Stanley Expansion Capital.

Graph databases can be used to answer queries with diagrams and charts that illustrate relationships, such as showing how people in a group are related to one another.

Journalists investigating the Panama Papers, documents showing offshore tax havens used by wealthy individuals, used a graph database to help sort through 2.6 terabytes of data, including emails, PDFs and images.

The database found relationships between names, which gave journalists leads to follow, according to a blog by an editor of the International Consortium of Investigative Journalists, which led the Panama Papers investigation.

The latest fund raising brings Neo4j’s total fund raising to $160 million. The company, based in San Mateo, California, did not disclose its valuation.

Emil Eifrem, Neo4j’s chief executive and co-founder, said his graph database has been used by bank clients to detect fraud and money laundering and also by retail clients to make recommendations for customers. Artificial intelligence platforms also are drawing on graph databases, he said.

“We’re getting an early signal of graph being used for the back end of AI and we are going to invest heavily into that,” Eifrem told Reuters by phone.

Neo4j says that its more than 300 customers include UBS, Walmart, eBay, Adobe and AstraZeneca.