Louise White
Louise White claims the $336m Powerball prize. ABCnews

An 81-year-old woman has been revealed as the lucky winner of the sixth largest lottery win in US history after winning a staggering $336.4m (£214m).

Rhode Island lottery officials confirmed that Louise White of Newport was the winner of last month's Powerball jackpot.

White, who lives with her son LeRoy, a musician, and his wife Deborah, a nurse, said: "I'm very happy and I'm very proud, and this will make my family very happy."

She appeared to take the bonanza calmly as she accepted the cheque from Rhode Island governor Lincoln Chafee.

He commended her for hiring professional legal help and setting up a trust before coming forward about the win.

He said: "Not only were you lucky, you were very smart. You took your time and you hired professionals."

White's attorneys revealed that the funds will go to the Rainbow Sherbert Trust, named after her son's favourite dessert, which she set up in February while buying the lottery ticket.

According to a family spokesman, after she realised she had the golden ticket she kept it safely in her Bible until she was able to go the bank and put it in a safety deposit box.

She opted to receive a reduced lump sum payment of $210m, rather than the 30 annuity payments offered.

She is expected to pay about $52.5 million in federal taxes and $14.7 million in state taxes.