PARIS -Hackers have stolen the private details of potentially millions of customers from luxury brands Gucci, Balenciaga and Alexander McQueen in an attack on the labels' French parent company Kering, the BBC reported on Monday.

Kering confirmed the breach in a statement without naming the affected brands, saying it identified in June that "an unauthorised third party gained temporary access to our systems and accessed limited customer data from some of our Houses".

The attack appears to be part of a wider phenomenon affecting luxury brands and retailers this year.

Breaches have also occurred at Richemont's Cartier and some of LVMH's labels. In July, Hong Kong's privacy watchdog said it was investigating a data leak affecting about 419,000 customers at LVMH's Louis Vuitton. 

The stolen client data includes names, email addresses, phone numbers, addresses and the total sums spent at the brands' stores, the BBC report said.

Kering said no financial information, such as credit card or bank account numbers, was stolen.

The hackers, who identified themselves as "Shiny Hunters" to the BBC, claim to have data linked to 7.4 million unique email addresses.

Kering said its brands immediately disclosed the breach to relevant authorities and notified customers according to local regulations. It did not comment when asked by Reuters which countries were affected by the attack.