A Herald on Sunday survey of nearly 1000 senior Government employees from 100 state owned enterprises, universities and ministries found:
More than half of senior executives spend above their monthly pricing limits, in some case by thousands of dollars.
A quarter of senior executives were stung by costly international data roaming charges, despite free WiFi being commonly available in hotels and airports.
State owned enterprise bosses spending more than $5000 a month on mobile charges.
Staff members are routinely given $1000 BlackBerrys.
Public service executives defended the charges but Opposition MPs said the findings raised serious questions.
Labour state services spokesman Chris Hipkins said: "There isn't a good excuse for racking up these kind of bills.
"The fact that these people are going ahead and downloading huge amounts of data suggests a certain laissez-faire attitude to spending public money."
Hipkins said most hotels and airports provided free WiFi, which should be used instead of the internet on smart phones.
"If they are downloading a work-related app then that's fine but if it's the latest version of the Angry Birds then that's not something they should be doing on mobile phones."
The single largest monthly spend was a Genesis Energy employee's $5072 bill in February. The senior executive was overseas for several weeks.
Genesis Energy spokesman Richard Gordon said the bills were acceptable costs.
"We do have guidelines around what is acceptable business use."
Industrial Research Limited chief executive Shaun Coffey spent $7677 over 15 months, including $2163 in one month.
A spokesman said: "Given the nature of IRL's business and the level of activity that the chief executive undertakes, that's a reasonable amount of the cost of the business."
Executives at our financial watchdog, Commission for Financial Literacy, were among the higher spenders.
Retirement Commissioner Diana Crossan spent $2364 over 15 months, and the executive director David Kneebone spent $2344.
Kneebone said all mobile phone charges were made in the course of day-to-day business.
Their mobile phone policy warns staff: "Employees are to be aware when using their cellphones the commission is charged at a casual rate for calls, text and data usage.
"Be aware this can add up quickly."
Seven senior staff from the New Zealand Security Intelligence, which provides all government agencies with security, spent an average of $141 a month on mobile phone calls, text messages and internet data.
But one manager, identified as senior manager two, stood above the rest with an average of $415 a month - almost three times more than colleagues.
Director of security Warren Tucker said the manager's increase was due to travel commitments and "the nature of the role".
"I can confirm that personal use of official mobile phones is closely monitored and staff are required to reimburse any costs in excess of $5 per month incurred in the use of official mobile phones for private purposes," Tucker said.
Mobile phones rentals were also soaking up taxpayers' dollars with some agencies paying more for the rental of phones than usage.
The Tertiary Education Commission spent almost $4000 on renting mobile phones compared with $3000 worth of usage.
At Environmental Science and Research, senior staff spent thousands above their fixed charges in the past year.
A State Services Commission spokeswoman said agencies were expected to have spending policies in place for staff to effectively undertake their roles and get the job done.
In April, the Government ushered in a new system of bulk-buying mobile phone contracts through Vodafone, Telecom and 2Degrees.
The stated aim was to avoid "bill shocks and hidden costs".
The usage of data while overseas was the common culprit for increases in expenditure.
Sport NZ chief executive Peter Miskimmin received a $10,000 data bill and $1131 phone bill for September and October last year.
Marketing manager Laurie Edwards said the majority came from using a laptop during a two-week trip to Europe.
Miskimmin met international sport organisations, including Sport England, UK Sport, UK Youth Sports Trust, Sport Scotland, and the Irish Sports Council.
"The purpose of the trip was to learn what makes these organisations successful," Edwards said.
Edwards said staff were educated on efficient use of their phones.
"We will continue to research how we can keep down these costs in future, such as through pre-paid sim cards or the use of internet technology."
Global roaming a killer
The impact of roaming phone charges is illustrated by the experience of the Northland District Health Board's chief executive.
Nine senior staff at the Northland District Health Board spend $12,000 on cellphone use during a 15-month period, average monthly expenditure of $88 per person.
But chief executive Nick Chamberlain, who at the time was general manager of clinical services, had one monthly bill of $774.45, in June last year.
During his last year in charge of clinical services, Chamberlain averaged just over $100 each month.
Northland District Health Board spokeswoman Liz Inch said Chamberlain was working overseas and relied on his cellphone to contact hospital services.
"During this time, Nick wasn't able to use the Citrix service because of technical difficulties [and] therefore relied on global roaming data access," Inch said.
Citrix is a system for off-site staff to access files and use the health board's intranet.
Inch said personal spending on mobile phones was carefully monitored.
