Sean Daniel Murphy, a senior constable with NSW Police, is “appalled” by his conduct after he said he wanted to rape Greens senator Sarah Hanson-Young's daughter during a phone call made to her electorate office, a court has heard.

Murphy has pleaded guilty to making the offensive remarks during a brief call to Senator Hanson-Young's Adelaide office in July.

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Court documents released this week show a Greens campaign manager answered the 57-year-old’s call before the officer asked: “Can I have a picture of the senator's daughter?”

He was told no and asked why he would want such a picture, to which he replied in an aggressive manner that he wanted to sexually assault the girl, according to the tendered fact sheet.

Murphy told federal police in a recorded interview three weeks after the call he didn't know if he'd made the offensive comment as he'd been drunk.

The 57-year-old is charged with using a carriage service to menace, harass or cause offence.

His barrister John Davidson told the Downing Centre Local Court on Tuesday that his client was "appalled by his conduct" and offered to apologise in person to Senator Hanson-Young.

Mr Davidson said Murphy had been receiving psychiatric treatment in hospital for post-traumatic stress disorder after three decades of police work on the street.

Magistrate Jennifer Atkinson agreed to place Murphy on bail on the conditions he not contact any witnesses or the senator's electorate office and that he reside either at a Campsie address or the Wollongong hospital where he is being treated.

Senator Hanson-Young in a statement on Tuesday described the threats as "vile" and said it has been "deeply distressing" for her, her family and staff.

NSW Police said Murphy was currently suspended. He will be sentenced on February 1.