Derrinallum's Geoffrey Spillman pleads guilty to sex offence.

A DERRINALLUM takeaway shop owner who masturbated while watching pornography in an area frequented by staff is being assessed to do a corrections order.

Geoffrey James Spillman, 62, of Ligar Street, pleaded guilty  in the Warrnambool Magistrates Court to committing an indecent act in the presence of a child.

Magistrate Michael Coghlan ordered a pre-sentence report be prepared by Office Of Corrections staff before Spillman is sentenced on Thursday next week.

​Police said Spillman was seen masturbating with his hand down his pants while watching pornography and one time had his pants pulled right down​.

One complainant said she felt uncomfortable and Spillman's actions "freaked me out".

Spillman, who served as a prison guard at Pentridge Prison for 10 years, told police "sometimes I get a bit excited".

He said he masturbated to fill in time during long hours in the shop which was closed mid last year and has now re-opened with a new owner.

In a victim impact statement, a young woman said she felt ashamed, embarrassed and terrified.

She resorted to self harm in an attempt to calm her anxiety.

On top of any penalty imposed, Spillman will also be put on the sex offenders’ register for eight years.