Alex Salmond impersonated a zombie by outstretching both arms and walking “clumsily” towards a woman he tried to kiss making her feel she was in an “awful nightmare”, a jury heard on Friday.

Woman J, a Scottish National Party worker, told the High Court in Edinburgh the alleged late-night sexual assault at the former first minister’s official residence was “premeditated” leaving her “freaked out”.

Giving evidence at the end of the first week of Mr Salmond’s trial, she claimed she and the then SNP leader had been working on documents for his independence referendum campaign in September 2014.

After returning from an official dinner, she was concerned the politician was “angry” after he learned of a breaking news story that would affect his independence campaign.

However, he became “more relaxed” as the pair worked in the living room in Bute House and his planned appearance on the Good Morning Scotland radio show.

Speaking from behind a screen, she told the jury of nine women and six men she felt “very much on edge” and “alone” in the Georgian building in a square in Edinburgh’s New Town.

After giving her a quick “tour” of the residence, he changed out of his suit into more “casual” clothing before lying on the floor and telling her “come here”.

Explaining how she did not “want to anger him”, she said she joined him on the floor to help amend a printout of documents they were working on.

“Out of the blue he said, ‘Have you seen that zombie movie?’,” she continued. “I was completely taken aback. I didn’t have a clue what he was talking about. He said, ‘Stand up a second.’

“I don’t think I had time to react. He stretched his arms out straight towards me and for a second or two did an impression of a zombie walking towards me.”

She said he took a couple of “clumsy steps” before putting his hands – with a “heavy touch” – on her shoulders and “leaned in” before moving her “out of the way” to kiss her on both cheeks before trying to kiss her on the lips.

Woman J said she “raised” her arms to “break contact” with Mr Salmond, adding: “I took a couple of steps back, he turned around to pick up the documents and acted like nothing had happened.”

She said she felt “scared… humiliated… devastated” and in “complete shock”, explaining she did not understand what had happened and struggled to “process” it.

“I remember thinking that I was glad that his reaction wasn’t angry,” she added.

She told the court how later in Mr Salmond’s study she “freaked out” when he touched her nose, and became “startled” when he “briefly” touched her leg and face.

She said they had gone to the study and engaged in “chit chat”, agreeing the room was cold.

She said he commented: “Well, you shouldn’t have bare legs.”

Asked by Alex Prentice, QC, for the prosecution, how that made her feel, she replied: “I took offence to it. I couldn’t have been more appropriately dressed, and I was wearing tights.”

She said he briefly put his hand on her leg above the knee, allegedly exclaiming: “Oh yes”.

She claimed she “froze”, in part because she felt “hemmed in” while sat at his desk in front of his computer.

“Apart from the security guards, we were essentially alone. There was no one else in the building,” she added. “I felt in a curious position.”

Mr Salmond left the room while she worked “quite a while” on the documents.

She said she declined his offer to stay over in one of the rooms.

When Woman J left Bute House in the early hours of the morning she said she was feeling “quite emotional”, but “with hindsight” believed “it was all premeditated”.

Asked how she felt the next morning, she replied: “Like I had had an awful nightmare.”

Under cross-examination by Shelagh McCall, QC, a defence advocate for Mr Salmond, she accepted the former First Minister was a “touchy feely” kind of person The SNP worker said she had thought her experience was “a complete one off” but was “dumbfounded” when she read later media reports of more alleged complaints against Mr Salmond.

She also accepted that in a statement given to police she did say: “I didn’t really understand what had happened to me. I didn’t think I had been a victim of something.”

She rejected Ms McCall’s suggestion that the “zombie impersonation” never actually happened.

Mr Salmond, 65, from Strichen, Aberdeenshire, denied 14 counts of sexual assaults against 10 women.

The trial continues.