Estimate, a racehorse owned by the Queen and trained by Sir Michael Stoute, has tested positive for morphine, a prohibited substance, Buckingham Palace announced.
Initial indications are that the positive test resulted from the consumption of a contaminated feed product, the palace said.
More top news
We'll have to wait until the weekend but by then it will be warming up.
Facebook says it will start test flights later this year of a solar-powered drone that aims to provide remote areas with the internet.
Children's charity Kids Company is being investigated by the Metropolitan Police over criminal allegations.