BOBIGNY, FRANCE (AFP) - Christmas came early for a French homeless man at Paris's main airport who found an unlocked door at the offices of a cash handling company... and walked away €300,000 (S$476,000) richer.

The man was rumaging through bins at the Charles de Gaulle airport northeast of Paris last Friday (Dec 8) when he checked a door at the Loomis cash management company and found it had been left open.

The door led to a compartment containing two bags filled with money.

An investigator, confirming a story that first appeared in Le Parisien newspaper, called it "the perfect crime" and said police still "don't know why the door was open at the time."

"At first we thought it had to be a setup, but it looks like it was just luck. It's incredible," a police source told AFP, asking not to be identified by name.

Investigators are searching for the suspect, who is believed to be in his 50s and has been identified by airport police.