Rihanna has ''unfollowed'' ex-boyfriend Chris Brown on twitter.

The 'You Da One' hitmaker - who was rushed to hospital suffering with ''exhaustion and dehydration'' on Tuesday night (08.05.12) - has deleted the rapper from her social networking account after speculation emerged that a seemingly offensive song he released last night (09.05.12) is aimed at the Bajan beauty.

Chris - who also ''unfollowed'' Rihanna on twitter following her actions - posted a link on the social networking site to his freestyle version of Kanye West's 'Way to Cold', formerly known as 'TheraFlu'.

In the song, he raps: ''Don't f**k with my old b*****s ... like a bad fur ... every industry n***** done had her,'' and it continues: ''Trick or treat like a pumpkin ... just to smash her.''

Following speculation that the song is aimed at Rihanna, Chris tweeted: ''Assumptions! I didn't say any names so if u took offense to it then its something you feel guilty about. (sic)''.

Rihanna, 24, has attracted a lot of criticism for seeing Chris after he was convicted of assaulting her in February 2009, and the 23-year-old rapper recently collaborated with the singer on her song 'Birthday Cake' earlier this year.

But the 'Umbrella' hitmaker has previously insisted she will not stop seeing Chris just because other people want her to.

She explained: ''I respect what other people have to say. The bottom line is that everyone thinks differently. It's very hard for me to accept, but I get it.

''People end up wasting their time on the blogs or whatever, ranting away, and that's all right. I don't hate them for it. Because tomorrow I'm still going to be the same person. I'm still going to do what I want to do.''