The incident occurred at around 3am on Saturday morning while Pinault was asleep. Salma Hayek was not there as she is currently in California with the couple's daughter.
According to Le Parisien, Pinault heard the sound of a door being opened and got up to find out who was in the building. He called out to ask who was there and caught sight of torchlight being pointed towards the floor. Calling out again disturbed the intruder who fled down the stairs and ran out the front door.
The newspaper reported that Pinault told police nothing was stolen by the intruder. He also said he doubted this was a "simple thief".
A police source quoted by Le Parisien said "the victim said he had put some bank cards and his laptop in the entrance hall and everything was still there. Nor had the person touched the impressive collection of luxury watches." According to police, Pinault himself had suggested it could be an "over curious fan".
Police also said that Pinault thought whoever entered the apartment knew it very well and had moved around with ease.
A further theory is that the intrusion could have been industrial espionage. 49-year old Pinault runs the PPR group which owns a series of luxury brands and well-known companies, including Yves Saint Laurent, Gucci and the French music, TV and electrical chain Fnac.
Police said that Pinault confirmed various offices of the company in Paris have been recent targets of break-ins. He added that the company is currently involved in various sensitive deals yet confidential documents in a briefcase in the entrance hall had not been touched.