A 42-year-old school teacher has been charged with the alleged sexual assault of a 15-year-old girl on NSW’s Central Coast after he was arrested at Sydney Airport.

Child Abuse Squad detectives began investigating a report the teenage girl was assaulted on Saturday, before they executed a search warrant at a unit in Kincumber about 5.55pm yesterday.

Officers seized a car and laptops for forensic investigation.

At approximately 6.30pm detectives arrested a man at Sydney Airport, where they will allege he was planning to travel to South Africa via Perth.

He was later taken to Mascot Police Station, where he was charged with seven counts of aggravated sexual intercourse with children aged 14 and 16, three counts of intentionally sexually touching children aged 10 and 16, and grooming a child for unlawful sexual activity.

The man was refused bail, and police will allege the school teacher sexually assaulted the girl multiple times in August and September.