Police officers are tracking the online activity of a Rihanna fan suspected of sending her a death threat on social media.

The Los Angeles Police Department are reportedly searching phone, computer and social media records after a man uploaded a 'selfie' photograph of himself outside Rihanna's former home in April (15).

It is alleged he also sent a death threat to the star, writing that he was about "to get a gun licence" and "should of killed (sic)" her.

Officers went to a property where the suspect was believed to be staying but he had already left, so they are monitoring his movements online, according to TMZ.com.