A visit to a Seoul escort-karaoke bar by a party of Uber execs in 2014 led to a HR complaint from a female employee

In 2014, Uber CEO Travis Kalanick, his then-girlfriend Gabi Holzwarth, and five Uber employees visited an escort-karaoke bar - an outing that prompted a complaint to HR from a female marketing executive at the company who was a member of the party, The Information's Amir Efrati reports.

According to the report, women working at the bar wore numbered tags and sat in a circle, so men could identify their favorites.

"Four male Uber managers picked women out of the group, calling out their numbers, and sat with them," the report claims.

Holzwarth and Kalanick left after "about an hour," according to Holzwarth, who gave an interview to The Information about the alleged incident.

The female marketing manager reported the episode to HR a year later, saying it left her feeling uncomfortable, The Information reports. The female Uber manager and Holzwarth discussed the matter over an instant messaging service. Holzwarth said she also brought the matter up with Kalanick.

The female Uber manager reportedly told Holzwarth: "[I]t made me feel horrible as a girl (seeing those girls with number tags and being called out is really degrading)."

The world's most valuable startup has been rocked in recent months by high-profile allegations of sexual harassment, some of which were outlined in a bombshell report from The New York Times about the company's internal culture. In February, the company hired ex-US attorney general Eric Holder and his partner at his Covington & Burling law firm, Tammy Albarran, to conduct a review of the claims.

It is that investigation that brought the details of the 2014 escort karaoke bar trip to light, according to The Information.

Holzwarth - who stopped dating Kalanick last year - alleges one of the execs who was in the party that night, Uber's senior VP of business Emil Michael, called her out of fear the press would dig up information about the outing.

Michael reportedly asked Holzwarth to tell journalists asking about that night to say the party had only visited a standard karaoke bar.

However, Holzwarth told The Information she would not have gone public about the incident, had Michael not attempted to keep her silent: "I'm not going to lie for them."

Uber did not immediately respond to a request for comment. A spokesperson for the company told The Information: "This all happened about three years ago and was previously reported to human resources. In early March it was referred to Eric Holder and Tammy Albarran as part of their review."

Michael also gave a statement to The Information.

He said: "Given the intense news cycle I thought it was the right thing to do to reach out and let her know that reporters may try to contact her directly. I have known her for a long time, consider her a friend and did not want her to be taken by surprise. Her recollection of this conversation was different from mine and I am very sorry if the purpose of my call was misunderstood."

You can read The Information's full report here (subscription required).