A woman has filed a complaint with German police alleging she was told to squeeze her breast at airport security to prove she was lactating.
Gayathiri Bose told the BBC she was "humiliated" by the experience and would explore formal legal action.
She said police at Frankfurt Airport were suspicious because she was carrying a breast pump but travelling without her baby.
German police denied she had been asked to prove her ability to breastfeed.
They had earlier declined to comment on the specific allegations but said such measures were "clearly" not part of routine procedure.
'Where is your baby?'
Ms Bose, who was travelling alone, said she was on her way to board a flight to Paris last Thursday when she was stopped at the security screening station.
The 33-year-old Singaporean said that after her carry-on bag, which contained her breast pump, went through the X-ray machine, she was taken aside for questioning.
"[They had] an incredulous tone. 'You are breastfeeding? Then where is your baby? Your baby is in Singapore?'," she said.
Ms Bose said the officers did not seem to believe her when she insisted the device was a breast pump.
They kept her passport and she was then led to a room by a female police officer for further questioning, she said.
Inside the room, the police officer asked her to prove she was lactating, claimed Ms Bose.
"She asked me to open up my blouse and show her my breast. She then asked how come I didn't have anything attached to my breast, if I was lactating and expressing breastmilk," said Ms Bose.
"And I said, there is no such thing that is [permanently] attached, we usually place the pump to our nipple and the machine does the job.
"She wanted me to show her by hand-expressing a little."
Ms Bose said she complied and squeezed her breast. "I was just in shock, I was going through the motions. I was all by myself as well, and wasn't sure what would happen to me if they decided to make trouble for me."
"It was only when I came out of the room that I began to slowly understand what had just happened. I just started to cry, I was terribly upset."
She said officials then tested and cleared the pump before returning her passport, and she was allowed to board her plane to Paris. Ms Bose asked for the name of the female officer, who wrote it on a piece of paper.
Ms Bose said the incident, which lasted for nearly 45 minutes, was "humiliating" and "very traumatising".
"When they finally cleared me of the matter, I told them that this is not the way to treat someone. I said 'Do you know what you just did to me, you made me show my breast.'
"The officer just said, 'Okay it is over now, please go'. She was totally nonchalant, she didn't seem very remorseful or empathetic."
Ms Bose, a manager at a transport company who has a three-year-old child and a seven-month-old baby, said she was exploring the possibility of taking formal legal action.
"While I do respect the need to do security checks on items that may seem suspicious, to outrage a person's modesty is definitely crossing the line."
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'This is not normal'
A Frankfurt airport police spokesman confirmed that Ms Bose had been stopped for checks and her breast pump checked as a possible suspected explosive.
But he denied that Ms Bose had been asked to squeeze her breast by their female officer.
"The federal police has been aware of the allegation since Friday. The investigation revealed that a necessary follow-up was carried out by the policewoman, who is a mother of two children herself," said a police statement emailed to the BBC.
"We deny the allegation that the passenger was asked to prove her ability to breastfeed."
Aviation expert Ellis Taylor from aviation publication Flightglobal said asking a mother to show she was lactating was "pretty ridiculous".
"This is not normal. There are some people representing authority who do overstep the mark, but that to me sounds unprecedented and quite frankly very humiliating."
He said the usual protocol in such a situation would involve an X-ray, followed by a check for traces of explosives on the item.
Officers may also ask the passenger to switch on the breast pump to show it works.
"But to hold an interrogation to demonstrate the passenger has a need for this device is bizarre. What if it were a man transporting the device? He would not be able to show he's lactating," said Mr Taylor.
Additional reporting by the BBC's Mal Siret