Deputy Chief Constable Paul Leighton made the revelation while defending the PSNI’s refusal to sack the officer who fronted a high profile anti-drink-driving TV advert — despite her being convicted of drink-driving.

Yesterday Mr Leighton faced fierce criticism after saying that in certain circumstances officers guilty of drink-driving could remain in their jobs.

In May 2006 he had warned that any officer caught breaking the law would be sacked or forced to resign.

Constable Geraldine Donnelly has returned to work after pleading guilty last May to the offence. She was fined £120 and banned from driving for 12 months.

Following her offence she was edited out of a television advert warning of the dangers of driving under the influence.

While Mr Leighton stressed it was wrong for motorists to consume alcohol, yesterday he defended the decision to allow Constable Donnelly to retain her job because the incident preceded the PSNI’s dismissal policy.

But he also told a radio phone-in: “I am not going to hypothesise about issues in cases in court where someone has maybe had a glass of wine and someone takes ill in the household and there is no ambulance available and they rush someone to hospital.

“Those are hypothetical circumstances, but those are exactly the type of circumstances that must be allowed for in any process.

“Since we made our policy statement in May 2006, any case post that date that has come to hearing, the officer has been either required to resign or has been dismissed.

“That is not to say that there may not be a case where there are mitigating circumstances that allow a tribunal to allow that officer to remain in post.”

But the chief executive of the Belfast company that creates the DoE anti-drink-driving TV adverts slammed any notion of driving after drinking being acceptable.

“It is just absolutely obscene that anyone should try to justify a situation where it is possible to have some drink and drive,” said Lyle Bailie International’s David Lyle.

Mr Lyle, who told the News Letter that he was not referring specifically to Mr Leighton when he made the comments, said there could be no excuses for motorists being over the alcohol limit.

“I hope all companies follow our lead and make it a part of employees’ contacts that being convicted of drink-driving is a sackable offence,” he said.

The deputy chief constable’s comments were also denounced by Lurgan woman Ursula Quinn, whose teenage daughter Shauna was killed five-and-a-half years ago in a car crash in Co Laois.

Ms Quinn, who works with lobby group Hidden Victims of Road Deaths, accused the Deputy Chief Constable of sending out mixed messages.

“The drink-driving message was getting through,” she said.