Rihanna is reportedly refusing to pay a $150,000 bill for her grandmother's funeral.

The 'Diamonds' singer is being sued by the company who organised the send off for her grandparent, Clara 'Dolly' Braithwaite - who died of cancer - in her native Barbados last July.

According TMZ, the lawsuit says Rihanna claimed the bill was exorbitant and refused the balance, paying only a quarter of the final bill.

The 25-year-old star allegedly spared no expense on the proceedings which included a party complete with tents, multi-media large screens and huge exotic floral arrangements.

Rihanna shared a close relationship with her grandma and was often pictured by her bedside during her battle with cancer.

In the wake of her death, Rihanna cancelled concerts and paid tribute to her, writing on Twitter: ''Goodbye grangranDolly get your beauty rest until I see you. grangranDolly that is all.''

Although she is said to be unwilling to pay the huge funeral bill, Rihanna donated $1.75 million to the radiotherapy department of the Queen Elizabeth Hospital in Barbados, in honour of her relative, through the Clara Lionel foundation.