A lottery in the Philippines that saw 433 people hit the jackpot has drawn surprise and triggered scrutiny.

It was the highest number of people to have ever won the Grand Lotto’s top prize, according to local media.

The winning combination for last weekend’s 236m peso ($4m; £3.5m) jackpot was a series of numbers which were all multiples of nine.

Philippines senate minority leader Koko Pimentel has called for an inquiry into the “suspicious” results.

Participants in the Grand Lotto select six numbers from one to 55. To win the jackpot, all six of a player’s numbers have to match those drawn by the lottery’s operator.

“These lotto games are authorised by the Republic of the Philippines. Therefore, we need to maintain and protect the integrity of these gambling games,” Mr Pimentel said as he called for an investigation into the lottery’s unusual outcome.

On Sunday, Melquiades Robles, general manager of the Philippine Charity Sweepstakes Office (PCSO), sought to reassure the public and said the drawing of winning numbers cannot be rigged.

The PCSO also highlighted that people in the Philippines tended to bet on number sequences.

“Many have held on to their numbers. It’s not only good to be loyal to your wives and husbands, it’s also good to be loyal to your numbers,” Mr Robles told a news conference.

The PCSO also shared photographs and videos of people collecting their prize money at its office in Mandaluyong city, close to the capital Manila.

“I’ve been betting on pattern nine, pattern eight, pattern seven and pattern six for many years and I’m thankful I just won,” one winner said.

Terence Tao, a maths professor from University of California, Los Angeles told the BBC that a pattern like this being a winning series of numbers is rare “for any single lottery”.

“But there are hundreds of lotteries every day around the world, and statistically it would not be surprising that every few decades, one of these lotteries would exhibit an unusual pattern,” he said.

“It’s similar to how in any given hand of poker it would be unlikely to draw a straight flush, but if one looks at hundreds of thousands of hands at once then it actually becomes quite likely that a straight flush would be drawn,” he added.

It’s not the first time a lottery has seen an unusual pattern or sequence of numbers drawn.

There were accusations of fraud after 20 people shared the jackpot in South Africa’s national lottery in December 2020, when the numbers five, six, seven, eight, nine and 10 were drawn.

The organisers said the winners collected 5.7m rand ($370,000; £278,000) each.

Meanwhile, a Spanish TV reporter resigned live on air after she thought she’d hit the jackpot in the country’s €4m ($3.9m; £3.4m) Christmas lottery.

Natalia Escudero started screaming on camera and told colleagues at public broadcaster RTVE she was “not coming to work tomorrow” – before later learning she had won just €5,000 ($4,349; £3,784).

And spare a thought for those whose lucky numbers came up in a lotto draw in the UK in March 2016.

More than 4,000 correctly picked five out of the six numbers – all multiples of seven – and ended up collecting just £15 each for their win.

You may also be interested in: