A Jetstar flight attendant has been stood down in Australia, after allegations that he contacted a 15-year-old female passenger, who had not given him her name, via Facebook soon after their flight.

The Melbourne girl's mother told Australia's ABC AM programme this week that the incident was "disturbing".

She said it raised concerns about the safety of teenagers flying alone.

It is alleged the Melbourne-based flight attendant, whose age was not released, first spoke to the woman's daughters, aged 15 and 16, outside toilets during their domestic flight.

The mother said her daughters did not tell the man their names but within hours of landing, the flight attendant had invited the 15-year-old to be his Facebook friend.

The mother believed the man must have got her daughter's details through the flight manifest but the airline has since said it came from a boarding pass.

"The male flight attendant is accessing ... the names of passengers, particularly my daughters, who are underage, and then he is using that information to contact them. I find that really disturbing," the mother said.

"I'm happy that my girls have blocked him, but I'm worried about, particularly during school holidays with teenagers flying all over the country on their own, that there have been some impressionable girls who have said, 'Hey, yeah, an older flight attendant. We'll add him'.

"I don't know where he's going with this. If the girls had added him, would he say 'Let's meet'?"

Jetstar spokesman Simon Westaway said the allegations were under investigation.