Ms Shriver is to donate her old mobile to a local charity for domestic abuse
The First Lady of California, Maria Shriver, has apologised for twice breaking a state law relating to using a hand-held mobile phone while driving.
It follows the publication of two photos by a well-known celebrity website of Ms Shriver driving her car while not using a hands-free device.
Governor Arnold Schwarzenegger wrote on his Twitter site that he would take "swift action" over his wife's actions.
Ms Shriver has issued a statement about donating her phone to a local charity.
Mr Schwarzenegger oversaw the introduction of a 2008 law in California which requires all drivers in the state to use hands-free mobile phones while driving.
Breaking the law carries a $20 (£12) fine for a first offence and a $50 (£30) fine if caught a second time.
Writing on the micro-blogging website Twitter, Mr Schwarzenegger said: "Thanks for bringing her [Maria Shriver's] violations to my attention. There is going to be swift action."
The First Lady of California has since issued a public statement on her website apologising for the transgressions.
"I'm sorry. I will be donating my favourite old cell phone to my Women's Conference partner Verizon... [an organisation] that helps domestic violence shelters," she said.
"I invite anyone else who wants to recycle their old phone to join me. That's my version of swift action with a higher purpose."