In Regal's notice of substantial holder released on September 1, Annexure 2, there's a list detailing Regal's purchases from August 2 to August 31. It totaled 39,237,030 shares. By then, Regal held 62,619,205 shares in total, meaning it held around 23 million shares before.
As for the top 20 shareholders, Regal purchased them under HSBC custody nominee, that's why Regal's name is not there.
Please do not accuse me of lying without any basis.