Update: CCTV footage is at the centre of the case against 20-year-old children's swim instructor, charged with sexual assault

Warning: this story contains some distressing details.

UPDATE:

The case against a 20-year-old swimming teacher, who is accused of sexually abusing two little girls in his care, centres around CCTV footage on the day it is alleged to have happened.

Kyle Daniels, 20, has been charged with having sexual intercourse with an eight-year-old girl and inappropriately touching another girl, aged 6.

Police said the alleged offences took place during lessons at the Mosman Swim Centre last month, in February.

According to Daily Mail Australia, detectives from the Child Abuse and Sex Crimes Squad have obtained the film from inside the swim centre which will be used as part of their evidence.

Daniels appeared in Manly Local Court on Wednesday and was refused bail until his next appearance on Wednesday.

EARLIER STORY:

Parents are reeling after a 20-year-old swimming teacher was arrested and accused of raping a young girl and inappropriately touching her sister.

Kyle Daniels, 20, appeared in Manly Local Court, Sydney charged with having sexual intercourse with an eight-year-old girl and inappropriately touching another girl, aged six.

The alleged offences took place during private lessons at the Mosman Swim Centre last month. Kyle Daniels worked as a swim teacher at the centre.

He went to the prestigious private school Knox Grammar and now attends the University of Sydney.

Daniels was arrested at his parents' home in Balgowlah after an investigation by detectives from the Child Abuse and Sex Crimes Squad.

He was charged with two counts of intentionally sexually touching a child under the age of 10 and having sexual intercourse with a child under 10. The girls are sisters.

Detective Superintendent John Kerlatec said Kyle Daniels had been a causal instructor at the swim school for two years.

'These young, brave kids put their hands up to mum and dad and said 'something happened'... That is exceptionally brave,' Detective Superintendent Kerlatec told reporters on Wednesday.

The swim centre said it suspended his employment before the police arrested the former private school boy.

On the website, the swim centre says it has 'a state-of-the-art, indoor, heated, 25 metre pool that is open to all members of the community'. 

Kyle Daniels was remanded in custody, but it is thought he will make an application for bail next week. His parents were in court, following the charges being laid.