A spokesman for Mohamed al Fayed, whose son died alongside Princess Diana in 1997, said he had no comment to make.
But it added that he will be "interested in seeing the outcome", and that he trusts the Metropolitan Police will investigate the information "with vigour".
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Chuka Umunna and Sam Gyimah, both of whom joined from other parties, failed in their bids to win seats.
Several people with lanyards on had to be pulled apart, with bystanders capturing the incident on mobile phones.
The Prime Minister retained Uxbridge and South Ruislip after finishing 7,210 votes ahead of his Labour opponent.