A man has gone on trial accused of raping his niece at her home in north Dublin in the early hours of St Stephen's Day 2014.

Her uncle, who is aged in his 60s, initially claimed he thought she was someone else but later told her mother it was consensual.

The man attended a large family gathering at his niece's house on Christmas Day 2014 and stayed back drinking after everyone else left.

She told the jury her daughter's room was free and he was supposed to sleep there but he followed her into her bed sometime after 4.30am.

She said they were both fully dressed when she fell asleep but she felt her trousers coming down at one point followed by a 'big, sharp pain'.

She said he was on top of her when she woke up and she pushed him off.

The court heard he initially told her he did not know it was her, but a few months later he sent her mother a letter claiming the sex was consensual.

The court heard he had taken a lie detector test and attached the results.

In the letter, he said what happened was '100% wrong but 100% consensual.

She strongly denies his version of events, and said she was totally disgusted when she read the letter.