Why is there an investigation looking into alleged betting about the general election?

Video caption, Why are people talking about election betting?

When the general election was first announced by Prime Minister Rishi Sunak in May it caught lots of people by surprise.

But now there are reports that a number of people allegedly placed bets on the date of the general election, when they may have already known when it would take place.

Sounds a bit complicated? We鈥檙e here to explain.