If the case turned out to be fraud, it would rank among the country's largest white collar crimes.
Other significant cases overseen by Mr Feeley during his three-year tenure include the SFO investigation into South Canterbury Finance owner Allan Hubbard which led to charges to the value of $1.7 billion.
The case never went ahead after Mr Hubbard died in a car accident. Other significant cases included the $100m case against DataSouth owner Gavin Bennett and the country's largest employee fraud of $17m by ASB Bank manager Stephen Versalko.