Heimdall - which bears the name of the sentinel god who guards the stronghold of Asgard and appears as a character in a series of Marvel movies - will analyse the documents that banks submit to the ECB for its fit-and-proper checks of prospective board members and key staff.

The software uses a natural-language processing model, meaning it can read information written by humans based on pre-defined rules, McCaul said.

"It relieves our supervisors of various manual and very time-consuming tasks, reduces the potential for human errors and frees up time to focus the supervisory judgement on the most critical aspects of each candidate's assessment," she told a banking conference.

In its fit-and-proper assessment, the ECB ascertains if a prospective banker has the necessary experience, reputation, independence and time for the role and looks for any conflict of interest.

(Reporting By Francesco Canepa; editing by John Stonestreet)