Mum asked to 'prove' son is hers before boarding flight

An American mother has accused Southwest Airlines for racially profiling her and her baby, after it demanded she show proof the child was indeed her son.

Lindsay Gottlieb says the question appeared to stem from her being white and her one-year-old son being biracial.

Ms Gottlieb was about to board a flight from Denver to Oakland when an employee at the gate stopped her.

"I'm appalled that after approx 50 times flying with my 1 year old son, ticket counter personnel told me I had to 'prove' that he was my son, despite having his passport," Ms Gottlieb wrote on Twitter.

"She said because we have different last name. My guess is because he has a different skin color."

Ms Gottlieb, who is the head coach for the University of California's Women's basketball team, says the airline wanted to see her son Jordan's birth certificate.

"She 1st asked for proof with birth certificate. She then said it's a "federal law" (not true) but asked me to prove I'm mother with Facebook post. What??"

The coach claimed another passenger stepped in, saying she had never been asked to "prove" her identity despite she and her child having different surnames too.

"Mother next to me said she's never been asked for proof despite diff last name..not shockingly, not mixed face fam."

She and Jordan were eventually let onto the plane but only made it because the flight was delayed.

Ms Gottlieb called the incident "demeaning and insensitive, not to mention inefficient".

"I'm emotionally drained from it and this is one day in my life and it's not normal for me," she told CBS News.

"It's one day for me and I know people experience things like this every single day which is why I reached out to Southwest and said, 'hey this isn't ok'."

The airline has since contacted Ms Gottlieb.

"We're looking into this specific interaction and we have engaged with the Customer directly to address her concerns," Southwest Airlines said in a statement to CBS News.

"Our Employees are well regarded for their Hospitality and we always strive for the best experience for anyone who entrusts us with their travel."

The airline has experienced a run of bad publicity recently.

In April, a female passenger died when she was partially sucked out of a window after one of the plane's engines exploded mid-flight.

And in May, a Southwest Airlines plane was forced to make an unscheduled landing when a large cracked appeared in a window.