Scotland Yard were investigating Saturday after reports that 3,000 photographs had been hacked from Pippa Middleton, sister-in-law of Britain's Prince William, and someone was trying to sell them.
The pictures were reported by The Sun and Daily Mail newspapers to have been stolen from Middleton's iCloud account and included shots of her sister Kate plus Prince George and Princess Charlotte.
Someone had been in touch with media via encrypted messaging service WhatsApp to offer them for sale, the reports added.
The Sun said it had been asked for £50,000 (58,000 euros, $65,000) for the shots.
The Metropolitan Police said in a statement: "On Friday, 23 September, police received a report concerning the alleged hacking of a personal iCloud account.
"Specialist officers are now investigating. No arrests have been made. Enquiries are ongoing."
Pippa Middleton, 33, is the younger sister of Kate and found fame after acting as bridesmaid at her sister's wedding to Prince William in 2011.
She is engaged to hedge fund boss James Matthews and the couple are expected to get married next year. The allegedly hacked photos also reportedly included shots of her wedding preparations.
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