A waitress who received a lottery ticket, that won $10m, as a tip, does not have to share the jackpot with her co-workers, a US court has ruled.

Alabama Supreme Court judges decided by five votes to two to overule a lower court's order that Tonda Dickerson had to split the pay-out with four other employees from the Waffle House restuarant.

Ms Dickerson's aggrieved colleagues had claimed they all had a verbal agreement to split any winnings.

But Justice Hugh Maddox said the verbal agreement amounted to a contract founded on "a gambling consideration" and was not enforceable.

Ms Dickerson, who now works at a different restaurant, had already started collecting her 20% of the pot while the court held the rest of the money in a bank account.

"We are absolutely thrilled," said her lawyer, Gary Holder.

Ms Dickerson was given the lottery ticket in March last year by regular customer, Edward Seward.

Mr Seward testified that he frequently left lottery tickets as tips.

He said that the restaurant workers had a standing agreement to share the proceeds, with the understanding they would buy him a new pick-up truck if they hit the jackpot.

However, the state supreme court ruled that this agreement was not legally binding.