Early risers are accustomed to the occasional late night straggler loitering on Sydney's Coogee Beach at sunrise.

But they are never normally this wild.

European red foxes have become a regular sight on Coogee's golden sands with bathers, walkers and group fitness classes all having recently witnessed the fearless predator's dramatic dawn dash home along the shoreline. The animals have also started to venture inside McIvers​ Baths, with one attempting to steal a swimmer's leggings a fortnight ago.

While fox populations appear to be on the rise across Sydney's densely populated eastern suburbs, councils say they are virtually powerless to halt their spread because of the dangers of baiting programs for domestic pets.

"Due to our location, we are restricted in what control measures we can adopt," a Randwick Council spokeswoman said last week. "We have previously employed cage trapping, which doesn't harm the fox or any off target species, however, no foxes were captured."

In 2015, the NSW government introduced a pest control order that paved the way for a "co-ordinated control" of the fox, an unwanted invasive species that reportedly costs Australia's environment and economy more than $227 million annually.

The order has enabled rural authorities to launch effective community-wide eradication programs. But it is a different story in built-up, residential areas. According to online mapping resource Foxscan, fox populations are flourishing along Sydney's eastern coastal fringes with Maroubra, Coogee and Tamarama topping the list of hotspots.

2GB presenter Natalie Peters was about to take an early morning dip last month when she saw a fox sprint across the sand towards the southern end of Coogee Beach. 

Another eye witness, Gary Cheer, photographed a relaxed-looking fox sitting on the shoreline staring out to sea.

And Coogee resident Bronwyn Morgan has had two recent encounters with foxes inside McIvers Baths, the most recent a fortnight ago when one attempted to flee with the cotton leggings she had left on a step.

"It looked at me, stepped forward, reached in through the fence wires and put its mouth around my trousers. It then took a step backwards with them. I can only presume it wanted them for its den or something. At that point, our eyes locked and I said something ... it then let go and casually walked off into the bush. It was a stunning looking creature," she said.

Neighbouring Waverley Council is also trying to outfox its growing population of cunning carnivores. It confirmed that while the majority of sightings go unreported, there were 15 eyewitness accounts last year, including one in Bronte where chickens were taken from a property, despite a two-metre protective fence. 

A spokeswoman revealed that as part of a recent combined Sydney Coastal Councils research program, it fumigated a number of active dens and undertook trapping so a live fox could be captured and fitted with a tracking collar. "This trapping was not successful despite a fox visiting the trap," she said.

Local Land Services, which provides pest control services to councils across NSW, told Fairfax Media that with "very tight rules" governing the use of effective baiting chemicals in residential areas, options were limited.

"The best estimate of fox density in urban areas is something around 10 per square kilometre. So even if you do remove two or three, reproduction will keep the population the same," Greater Sydney biosecurity manager Graham Wilson said.

He pointed out the biggest issue is that people in suburbia "like foxes" and think they are "cute".

"If you look at them without understanding what a serious invasive predator they are, then there is no disputing they are attractive looking animals," he said. "A lot of people still don't realise they are not native and are a serious problem."

He said urban fox populations would continue to thrive while food supply remains plentiful.  "Our most important message is to try to get people to stop leaving available food ... because a fox will eat anything."

Do you know more? eduff@fairfaxmedia.com.au