He described them as a "massive rort" and an attempt to "trick" Chinese-Australian voters.
Mr Hilakari said the posters read "the correct way to vote is to put a number 1 next to the Liberals and number every other box", and appear to be written like an official AEC instruction to voters.
"This is a rort. The Libs are trying to trick Chinese voters. Morrison's Libs should never have approved these signs," he tweeted on Saturday.
AEC spokesman Evan Ekin-Smyth said the posters did not need to be taken down as they were properly authorised and no laws had been breached.
"We don't own the colour purple, and it's not possible to do that. They just need to be appropriately authorised, which they are," he told AAP.
"While clearly the AEC would prefer no-one uses purple and (makes posters) to look like an AEC (poster), people can make posters so long as they are authorised appropriately.
"My understanding is that it meets the requirements of the Act. No law has been breached."
Bill Shorten said he had not heard about the incident.
"Always look at who benefits from the dirty tricks and that generally is the culprit, isn't it?", he told reporters.
A Labor spokesperson said the party had lodged an official complaint with the AEC.
"This is a new low - a pathetic and dirty attempt to deceive voters because the Liberals have no policy to talk about," they said.
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