A lighting engineer accused of raping a friend of his daughter at the Off Grid festival near Shepton Mallet last August has been found not guilty after a three-day trial.

Divorced father-of-two Roy Gwinn, 53, told Taunton Crown Court the 29-year-old woman, who had recently gained a degree in music technology, had worked for him twice before.

He collected her from her London home and had intended sleeping in his van while she used a tent.

But he was unable to unload all his equipment that night because the site was not ready and asked if he could use the tent as well.

James Patrick, prosecuting, said they had a drink and she wandered off because she was bored.

When she returned, he started trying to get close to her.

She was feeling a bit ill from the drink and went to bed but was woken up by Gwinn raping her, he alleged.

Mr Gwinn, who was said to be of good character, told the court he was divorced in 1997 and was introduced to the complainant by his daughter. She had worked for him on two previous events.

They arrived at the festival site at about 9pm but were able to install only some of his lights because the site was not ready.

They drank half a litre of vodka, chatted, and walked around the site and lay on the ground looking at the stars, he said.

He asked if he could sleep in the tent because he had not been able to unload the van and "got no impression my presence was unwelcome." She was still awake when he went to bed and did not object when he had sex with her, he added.

He said he remembered her with fondness when he briefly woke up about four hours later but she told him "It's not right – you're my friend's father".

After breakfast, she looked hungover and seemed withdrawn.

"I asked her if she was alright about it and she said 'yes but I don't want you to tell anyone about it.'"

He later received a Facebook message from her saying "I don't want to see you again," he added to the court.