Apple has suffered its worst stock decline in a month following a report that Chinese government agencies have barred staff from using the iPhone and other foreign-branded devices at work.

Employees at "some” central government regulators received instructions via chat groups and in meetings to stop bringing such gadgets into the office, said the Wall Street Journal, citing people familiar with the matter. It’s not clear how widely the orders were issued, the newspaper added.

The shares slid 3.6% to $182.91 in New York on Wednesday, marking the biggest single-day drop since Aug. 4. Apple had gained 46% this year before the decline, part of a broader run-up in tech stocks.