A woman in the US has been charged with using the Craigslist website to post a classified advert offering $50,000 in search of a killer for a romantic rival.

According to authorities, Ann Marie Linscott posted two ads in November and received at least three responses, apparently from people who thought the ad was for a freelance writing gig.

In email exchanges, however, Linscott, 48, told the job seekers that she was looking for "silent assassins" to "eradicate" a 56-year-old Californian woman named 'Carol', according to an affidavit from the FBI agent investigating the case. Carol's husband had been having an affair with Linscott after the two met several years earlier during an online college course, the affidavit states.

Linscott used the alias 'bourne2run' as part of her email address.

On Wednesday a California grand jury brought murder-for-hire charges against Linscott, who is now facing up to 30 years in jail and a $750,000 fine for her ad.