Nathan Harkness had been to a 40th birthday party in June when he drove through a red light outside Geelong and braked heavily before crashing into a parked car, which struck a second vehicle.

Melbourne Magistrates Court was told on Tuesday that Harkness, 38, a senior constable, drove from the scene about 9am as the other drivers readied to exchange names and addresses.

Prosecutor Julian Ayres told the court that soon after, and "coincidentally", his car was noticed with damage by other police members.

Mr Ayres said Harkness tested positive to alcohol and at 11.52am a blood test was taken that later revealed the high reading and also the presence of ecstasy.

Harkness, who is suspended, pleaded guilty to charges of exceeding the prescribed concentration of alcohol, careless driving, failing to stop after an accident and failing a drug blood test.

His barrister, Sean Hardy, told the court his client, a policeman since 2008, was married with three children, had no prior convictions and his chance of retaining his job "doesn't look good".

Mr Hardy said Harkness did not take drugs and believed his drink may have been spiked, but admitted he tended to binge-drink alcohol.

He would suffer hardship as a result of his poor judgment, he submitted, as the circumstances were "not going to assist him" in future applications for work.

Deputy Chief Magistrate Felicity Broughton told Harkness he was lucky his wife was not greeted at their front door with the news he had been killed or he had killed someone else.

Ms Broughton said he was "well aware of the carnage on the roads" and that he was "incredibly lucky" his type of drink-driving was not worse.

She told him he ought to have clearly known it was his duty to uphold the law and advised him that he needed to urgently and consistently address his issue with alcohol, but was confident "we will not see you back here again".

Harkness was convicted on all charges, fined a total of $2000 and had his licence cancelled for 19 months.