Keke Palmer "knew something was wrong" when a stranger proposed because she could see the ring was "expensive".

The Nope actress was sitting on a Baby, This Is Keke Palmer Live panel at the SXSW Festival last month when a man from the audience got down on one knee to ask her to marry him and she could quickly tell it wasn't just a prank.

Speaking on the Decisions, Decisions podcast, she explained: "This is how I knew that something was wrong because the ring was nice. It wasn't like no Cracker Jack ring.

"I'm serious, the ring looked expensive. It looked expensive. That's when I knew something was up.

"That's when I was like 'is this a joke' because it was so sincere. I could see in his eyes that we've had romance. We had a lifetime in this man's eyes."

Keke thought the man genuinely believed it was finally time to propose, even though they didn't know each other.

She said: "So then I was like, 'Okay, sir, no, I cannot marry you, I cannot marry you, sir.' And then that's when I knew when he started looking back to the people and he was like, 'She wants to say yes. Help her say yes.' And I was just like, 'Oh, no.' "

The Nope actress focused on being "careful" about how she rejected the man, who she said looked like a "pretty together guy", and only got nervous about the fact it could have been a dangerous situation afterwards.

She said: "This is nothing to play with. And that's why I just started feeling sad because I was thinking to myself, 'man, this guy is in a really bad way, man.' "

Despite Keke's public profile, she hopes people can understand she is "only human".

She added: "I hope that we can all start having these conversations around what it means to be an entertainer, what it means to be a celebrity, what it means to have impact and visibility."

Austin Police Department previously confirmed they had responded to a disturbance at the JW Marriott hotel in the city on the day of the incident after a caller reported that an individual refued to leave.

The cops alleged the man, who was identified as Kendall Demouchet, told them he intended to continue his attempt to propose to Palmer even after being told he had to leave the hotel.

He was arrested for criminal trespass and will appear in court on 27 April.