Ke$ha and John Mayer. (WENN.COM file photos)

John Mayer and Ke$ha have sparked rumours they are set to become Hollywood's latest celebrity couple - after exchanging flirty online messages.

The rocker, who has previously dated stars including Jessica Simpson and Jennifer Aniston, took to his Twitter.com page on Saturday night to express his admiration for her "tricks and charms" as well as her music, referencing a line in her hit track TiK ToK.

He wrote, "Dear Ke$ha, you have won me over with your tricks and charms and I must tell you I really like your song (TiK ToK). Though I must add I tried brushing with a bottle of Jack and I chipped a tooth on the glass. Where might I remit an invoice?"

He also told his fans to "stop telling your friends you detest the Ke$ha song and then dancing to it at home. How about some accountability, people?"

And Ke$ha quickly acknowledged her celebrity admirer, firing off a flirtatious response to Mayer's compliments.

She writes, "Dear John Mayer. Don't be a little b**ch wit ur (with your) chit chat. Jus $how (sic) me where ur d***'s at (sic). x"