Australian federal police are looking into whether David Jones and Kmart's websites have been targeted by the same hackers.
David Jones revealed on Friday the personal details of the department store's online customers have been exposed after hackers attacked its website.
This comes two days after Kmart revealed a similar incident, highlighting fears hackers are targeting major Australian retailers.
In both cases, no credit card details were exposed, however personal information, including customer names, email addresses, home addresses and telephone numbers, have been accessed.
The AFP is liaising with both retailers and will look into any links between the two incidences.
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"The AFP will consider all aspects of these two matters and any similarities or linkages will be closely examined," a statement from the AFP said.
There are no signs the accessed information has been misused, David Jones said.
The retailer said it has acted swiftly to prevent further exposure and is working closely with IBM on its internet platform.
Kmart has engaged leading IT forensic investigators.
David Jones and Kmart have declined to give further details, including the number of customers affected.
