The moves are not expected to result in charges against earnings.
Yet waiting too long could result in charges of negligence by residents.
Fraudulent use may result in criminal charges or a fine.
A police investigation into a child sexual abuse case had resulted in charges against a number of people.
Notice of being under investigation does not necessarily result in charges.
That earlier case has resulted in criminal charges against 17 people.
Many of the legal conflicts do not result in serious charges.
Roaming is also not included and will result in additional charges.
It said the plan would result in charges of about $225 million over the next three years.
It is not yet known whether the inquiry will result in charges against executives or the companies themselves.