The woman who complained about Red Bull team principal Christian Horner’s behaviour is “very upset, angry, scared, intimidated and lonely”, a family friend has told BBC Sport.

The woman lodged a complaint in December that contained allegations of coercive, abusive behaviour and sexual harassment by Horner.

She “struggles to understand” how Red Bull dismissed the complaint following an investigation, the friend added.

Horner has always denied the claims.

Red Bull dismissed the complaint on 28 February after an internal investigation and cleared Horner, 50, of any wrongdoing.

Until now, the complaint has been described as one of inappropriate and controlling behaviour. Red Bull said they could not confirm it also included allegations of sexual harassment, but BBC Sport has seen evidence to that effect.

The woman is unable to talk about her claims, having signed a legal undertaking not to discuss the matter with anyone other than her father and brother, the friend said.

“It’s impossible for people to understand what it’s like for her,” said the friend, who was talking to BBC Sport exclusively and on condition of anonymity. “She can’t talk and she won’t talk.

“But I can tell you what it is doing to her. Every time I have asked her something, she breaks down in tears and says she’s got no-one to talk to because she’s not allowed to talk.

“She is very upset, very angry, very scared, very intimidated, very lonely. And I think it’s impossible for people to understand without being in her shoes what it’s like for her.”

A Red Bull spokesperson said: “Both [parties] signed a confidentiality agreement on it so they both can’t discuss it.”