Fast food giant McDonald's has been given a ticking off after launching an email marketing campaign aimed at children.
The company posted a "send to a friend" facility on its Happy Meal website last year which encouraged visitors to email links for McDonald's-themed games to their mates.
The Australian Communications and Media Authority (ACMA) ruled the marketing campaign contravened the Spam Act 2003 because recipients didn't consent to receiving the emails and they couldn't unsubscribe.
The Spam Act states it is illegal to send, or cause to be sent, unsolicited commercial electronic messages.
McDonald's removed the link in February and on Tuesday was given a formal warning by ACMA.
"A formal warning is a fairly stern thing, particularly for a company the size of McDonald's," ACMA's anti-spam manager Julia Cornwell McKean told AAP.
ACMA warned companies running similar marketing campaigns, which are found to contravene spam laws, that they could face tougher punishments in future.
"Really this is our first 'friend get friend' investigation. It's a formal warning," Ms Cornwell McKean added.
"But business should take heed that it won't be next time."
A McDonald's spokesman told AAP: "McDonald's takes its compliance obligations very seriously and fully respects the finding of the ACMA's investigation.
"The 'send to a friend' function was removed from the Happy Meal website in February 2012 and McDonald's has no intention of reinstating the function or any similar functions on its websites."