They join a growing list of management casualties and now face a period of growing uncertainty to see whether they will be pursued by the FBI, which is investigating irregularities at 55 companies, many in the IT industry.

A 20-year veteran with the company, Caputo said: The issues related to stock options occurred under my leadership and I do not want my continued presence to be a distraction to the important work we perform for our customers every day.

Belcamp, Marylandbased SafeNet said last month that an investigation had revealed that certain option grants made between 2000 and 2005, which included grants to directors, had been accounted for using incorrect measurement dates.

It estimated that estimates the aggregate non-cash charges to be included in restatements of its accounts for the relevant period would be no more than $20m.

Independent director Walter Straub takes over as interim CEO while John Frederick becomes interim CFO. SafeNet said Caputo and Argo will be available to the company through the end of the year to assist in the management transition.

SafeNet stock, riding high at over $35 at the start of the year, has now slumped to $21.86.