UK Government ministers have been banned from using iPhones for official communications.
Guidelines issued by the Communications-Electronics Security Group (CESG) at GCHQ, Cheltenham, also advise Government departments against issuing iPhones to staff.
The CESG, the organisation that tests the security of Government communications, has instead suggested that ministers and staff continue to use RIM's BlackBerry smartphones.
BlackBerry devices have been certified secure by the CESG since 2006.
Apple has denied allegations that its iPhone is not secure.
In a written answer to the Commons, health minister Simon Burns said: "The only mobile telecoms or personal digital assistant devices that have been issued to Ministers of the Department are BlackBerry devices."
"The Department does not issue Apple iPhones to staff as these are not approved for Government use by the CESG," he explained.
Government security concerns over the iPhone follow a data leak by US wireless carrier AT&T that exposed the personal data of 114,000 iPad users, including officials at the White House.