A senior prison officer has been allowed to return home to his family a day after he was charged with the sexual assault of inmates at a western Sydney prison.

Key points: Wayne Astill, 62, is accused of sexually assaulting three inmates at a Windsor correctional centre

Wayne Astill, 62, is accused of sexually assaulting three inmates at a Windsor correctional centre He has been suspended from work with Corrective Services labelling the alleged behaviour as "unacceptable"

He has been suspended from work with Corrective Services labelling the alleged behaviour as "unacceptable" He denies the charges and his lawyer has argued Mr Astill has good character as he was granted bail

Wayne Astill, 62, embraced his prison guard partner Tanya Hockey before being driven out of Amber Laurel Correctional Centre at Emu Plains this afternoon.

The grandfather faced Penrith Court today, where he was granted strict conditional bail on the basis he surrendered his passport and stumped up a $20,000 surety.

The Kurrajong Heights man was arrested at his home, north-west of Sydney, yesterday following a joint investigation by NSW Police and Corrective Services NSW.

He was charged with 12 offences, including six counts of aggravated indecent assault and misconduct in public office.

The alleged sexual assaults of the three inmates took place at the Dillwynia Correctional Centre at Windsor between October 2016 and September 2017.

Wayne Astill allegedly sexually assaulted the inmates between 2016 and 2017. ( Supplied: Facebook )

The court heard Mr Astill initially denied having sex with the women, but changed his account when police showed him a secret recording from inside the prison, saying the sex was consensual.

In opposing bail, the police prosecutor Sergeant Callie Elwin described Mr Astill's alleged behaviour as "planned and calculated" and an "abuse of power".

But his lawyer Paul Blunt argued his client had strong community ties and only had one high-range drink-driving conviction dating back to 1982.

"He is a carer for an elderly relative, he has three investment properties, he has a family, he has built a life — so there is no risk of him fleeing," he said.

The court was told Wayne Astill first denied the sexual contact but later said it was consensual. ( Supplied: Facebook )

Outside court, Ms Hockey said she had been left shocked by the allegations and that it had been a very difficult time for her family.

"I just want to be left alone," she said.

"Of course, I'm glad he got bail."

Mr Astill has been suspended from work, with Corrective Services labelling the alleged behaviour as "unacceptable".

"CSNSW will continue to do everything it can to assist the investigation and the women involved," a spokesperson said.

"All inmates are being reminded of the avenues available to them to report any instances of such behaviour.

"Allegations of this nature are extremely rare and do not reflect upon the vast majority of our staff, who would be disgusted by these allegations."

Mr Astill denies the charges and is due to face court again on April 26.