M.I.A has accused her billionaire ex-fiance of trying to take their son away from her.

The 'Bad Girls' singer lashed out at wealthy environmentalist Benjamin Bronfman, who she split from in February 2012, and his family for allegedly trying to secure custody of their four-year-old son Ikhyd Edgar Arular Bronfman in a rant on her Twitter page on Wednesday (13.03.13).

The tweets, which have since been deleted, included: ''BEN you can't take my son away from me 'The mother'. Just because you have money doesn't mean you have ethe [sic] right.

''WOW. THE BRONFMANS WANT TO TAKE MY CHILD AWAY FROM ME. WHAT KIND OF S**T IS THAT? THEY NEVER SEE HIM

''Every child needs the MOTHER, I GREW UP WITHOUT A DAD. If grew up without my mother I wouldn't be here.''

The 37-year-old singer also retweeted a number of messages of support from her followers, including: ''The mother is way more important for a child than the father imo. He should think about that. I wish u the best. X''

M.I.A. - born Mathangi Arulpragasam in Sri Lanka - caused controversy in the US in February 2012 when she swore by flipping her middle finger at a camera during a live performance alongside Madonna at the Super Bowl XLVI NFL event, one of the most watched TV moments of the year.