Pictured: Woman who died by her husband's side in NSW bushfire

The elderly couple who died in a bushfire in northern NSW have been identified as Bob Lindsey and Gwen Hyde.

Mr Lindsey, 77, and his 69-year-old wife, Ms Hyde, were found dead in their home, which was destroyed by the Long Gully fire, in Coongbar.

The Long Gully fire flared up again on Tuesday and ravaged the area, including the couple's isolated property about 70km southwest of Casino.

Their bodies were found on Thursday afternoon.

Gwen Hyde (pictured) died in her home alongside husband Bob Lindsey in a bushfire. Source: Nine News

A close friend told The Daily Telegraph the pair married three years ago.

Both have children from past marriages.

Carol Dillon, a friend of the couple, told the publication she didn’t think they would have stood a chance as the blaze crept up on the property.

“I’m hoping it was very quick,” Ms Dillon said.

Local Ken Crowther said the couple was well known by everyone in the small community.

"It'll be fairly devastating for us all," he told Ten News.

The couple's home in Coongbar after it was gutted by fire. Source: Nine News

It has been determined the blaze was started by a lightning strike more than a month ago.

But Superintendent Toby Lindsay told reporters in Casino the couple’s deaths would be subject to an “extensive” investigation.

Premier Gladys Berejiklian sent her condolences.

"So saddened to hear about the loss of life in the bushfires in northern NSW," she tweeted.

"Our thoughts and prayers are with all of those affected."

Meanwhile, fire has destroyed about 30 properties in the northern NSW town of Rappville.

It is believed the fire that ripped through Rappville may have been deliberately lit, with NSW Emergency Services Minister David Elliott labelling the potential arson a "bastard act".

In total across the region, 72 outbuildings were destroyed, according to the Rural Fire Service's most recent count. Some 23 were damaged.

A ute passes a fire burning at Busbys Flat, near Rappville, in northern NSW. Source: AAP

Richmond Valley mayor Robert Mustow says the destruction of the Tarmac Sawmill in Rappville will hurt 30 employees and have a "big impact on our community".

The Brisbane to Sydney rail line has been cut and won't operate for an estimated five days, the mayor added.

NSW Transport Minister Andrew Constance said stretches of the rail line had been damaged and the Rappville rail bridge destroyed.

NSW Rural Fire Service Commissioner Shane Fitzsimmons confirmed the Busbys Flat blaze was being treated as suspicious.

"We've got to call it out - it's a heinous crime, a criminal act," he told the Nine Network on Thursday.

A house in Rappville destroyed by bushfire. Source: AAP

Strikeforce Cleander has been formed to investigate the cause of the fire.

Supt Lindsay insists the strike force "will leave no stone unturned so we can provide answers for the rural communities impacted by this disaster".

Teams are still assessing how many properties have been lost or damaged. So far this bushfire season more than 70 homes have been destroyed across NSW.

The Drake and Busbys Flat fires have scorched a combined 115,000 hectares.

With AAP

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