The bodies of Kenneth and Rita Boughey were discovered at their home in the Abbey development on Thursday night.
Ch Insp Mark McClarence said post mortem examinations "ruled out" carbon monoxide poisoning as a cause of death.
He said the deaths "continue to be treated as unexplained" as police await further toxicology test results.
Mr Boughey, 68, and Mrs Boughey, 79, were originally from Liverpool but had lived in Ballycastle for 10 years.
It is believed that the pensioners may have been dead for a number of weeks before their bodies were discovered.
The alarm was raised by Mrs Boughey's son on Thursday, and the police, fire and ambulance services were called to the scene.

First, the oil major is preparing for a low oil price for the foreseeable future, saying that it is working towards a "financial frame" by 2017 that assumes a price of $60 a barrel.
When I interviewed Bob Dudley at the start of the year, he said that low energy prices could last for three years.
Nothing since then seems to have changed his view.
"Last year, we acted decisively to reset BP for a sustained period of lower oil prices and the results are coming through well," he said today.
"We are now in action to rebalance our financial framework in this new price environment."
Second, low oil prices are not all bad news for integrated oil companies.
Yes, life upstream (the exploration and production part of the business) might be tougher because the business is not being paid as much for every barrel of oil it produces.
But, for the downstream business (that's refined oil products such as fuel, lubricants and petrochemicals for making things like paint and plastic bottles) a low oil price can be a veritable boon.
That's because the input costs - essentially the low oil price - are down and therefore the profit margin can be boosted.
If you compare the upstream and downstream profit numbers for BP, the difference is stark.
For upstream, pre-tax underlying profit was $800m (£520m) compared with $3.9bn (£2.54bn) in the third quarter of 2014.
That's a pretty precipitate drop.
For downstream, pre-tax underlying profit hit $2.3bn (£1.5bn) compared with $1.5bn (£980m) in the third quarter of 2014.
So, for the moment, BP's downstream business is creating considerably more profit than its upstream partner.
BP also revealed that the cost of the Deepwater Horizon disaster has now reached $55bn (£35.85bn).
When the Macondo rig blew up in 2010, killing 11 people and leading to a major oil spill, many predicted it would cost BP several billion dollars in clean-up costs, fines and compensation.
Few people foresaw just how high the price would be.
Or for how many years it would weigh on the company.
VW should take note. Scandals are more expensive than you initially think.
And take a lot longer to clean up.
An elderly couple who were found dead in Ballycastle, County Antrim, last week did not die as a result of carbon monoxide poisoning, police have said.
[NEXT_CONCEPT]
Two things are clear from BP's results this morning.