A British Airways steward held his phone over a cubicle door at Heathrow Airport to watch a man on the toilet, a court heard.
Andrea Cesqui, 36, pleaded guilty to voyeurism at Heathrow Airport Terminal 5 on October 21, last year - after he was pointed out in the staff canteen.
This was after his image was circulated amongst British Airways staff in an attempt to track him down.
He was fined £800 and ordered to sign the Sex Offender’s Register for five years.
Prosecutor Beata Murphy said: "On October 21 the victim entered the men's toilet of Terminal 5, went to the far-right cubicle and began to urinate.
"But he noticed that somebody had placed a mobile phone over the top of the cubicle doors. He could see the top of the phone with its rear side camera lens exposed. He looked into the lens and the person holding the phone immediately pulled the phone down."
Ms Murphy said the victim opened his cubicle door and saw the man leave the cubicle next to him.
He confronted Cesqui, who was "extremely nervous and agitated", outside the toilets and demanded to see his phone, the court heard.
Cesqui, in his BA uniform, only showed him "the back of the folder" and not the most recent files, which revealed multiple photos of different men's genitals.
The victim went to get a security guard but Cesqui had disappeared by the time they returned.
Ms Murphy said: "The defendant had a suitcase and backpack suggesting that he may have been a passenger.
"However the complainant believes he saw a uniform underneath his hoodie similar to those worn by airside passengers which would identify him as a Heathrow employee.
"CCTV showed him wearing what appeared to be British Airways uniform so his image was circulated to a selected few British Airways employees with a view to identify him."
A member of BA staff identified him in the Heathrow Terminal 5 staff canteen on November 19 and called police, which led to Cesqui's arrest.
His mobile phone was examined and despite numerous images of male genitals, none were of a "voyeuristic nature" and the subjects "appeared to be aware the photos were being taken".
The court heard that Cesqui was informed he would have to quarantine at the last hearing and probation services refused to interview him in person this morning.
But magistrates asked for the interview to take place over the phone so they could sentence him this afternoon as he is "already at court".
They heard Cesqui may have difficulty funding another trip to the UK from Malaga, where he currently lives if the case was adjourned.
James Riley, defending, said Cesqui had lost his job at British Airways as a result of the voyeurism charge and now works in a call centre.
He added: "It was a stupid thing to do and it was a one-off thing. As a result of this foolish act on his behalf, he has lost his job working for British Airways as cabin crew.
"He has no prospects of coming back to live in this country."
Sentencing him, chair of the bench Anthony Dorothy said: "We believe there is a degree of planning involved here. The placement of the mobile phone etc. It does not pass the custody threshold therefore we are going to deal with this by way of a fine."