When Betty and Brian Harris were told they had scooped the jackpot prize of £9,500 in The Argus Cross The Ball competition they were convinced it was a hoax.

The couple suspected it was Betty's sister, Carol, who was behind the 'joke'.

On discovering they really had won the competition they had been playing avidly for ten years, Betty, 66, and Brian, 68, devised a little trick of their own.

Betty, of Patcham, said: "As soon as the person from The Argus told me to sit down, I knew it must be the jackpot that we'd won. I said, 'I need to kneel down, not sit down.'

"I shouted through to Brian that we'd won and he said it must be Carol or her husband, Roger, trying to trick us."

Betty and Brian, both retired, have been keeping an eye on her sisters' houses while they are on holiday in the Isle of Wight.

The couple will not be ringing the sisters to tell them of their jackpot win, but are going to leave a copy of this paper open on their tables for them to see on their return.

Betty said: "My sisters play Cross The Ball avidly but they never tell us when they're runners up. They've won the second prize once and runner-up prizes about three times but they let us find out ourselves by reading it in the paper.

"We thought we'd get our own back. It will be a real shock for them to come home and see us in the paper."

Betty and Brian play Cross The Ball every week. They each draw 200 crosses on the photo from a Brighton and Hove Albion football match, but this time, Betty is sure hers was the winning cross.

She said: "It was my turn to pay this week and it was my cross that won."

Brian joked: "I'd better be careful or I won't be getting any of the money."

As they received their cheque on Friday, Betty and Brian were still in a state of shock.

After splitting the amount between them, Brian will buy a new car and Betty will put her winnings in the bank as well as giving some to her family and to charity.

The couple intend to have a celebratory meal but do not plan to go on holiday or fritter their money away.

The Cross the Ball competition goes up £500 each week if no one wins.