WELLINGTON (REUTERS) - Search operations were under way on Wednesday (Feb 12) for a British backpacker who went missing in the South Island of New Zealand after an intense flood in the area.

Ms Stephanie Simpson, 32, has not been seen since she went for a hike last weekend at the Mount Aspiring National Park, home to one of New Zealand's highest peaks.

Police started looking for Ms Simpson after she failed to keep an appointment on Monday and was reported missing.

"Search teams remained out in the area overnight," New Zealand police said in a statement.

"It is a large search area and much of it is difficult terrain," it added.

On Wednesday, drones with thermal imaging would be deployed in the area along with search and rescue teams on the ground and a helicopter, the police said.

Flash floods and incessant torrential rains hit New Zealand's South Island last week, leaving several hundred tourists stranded for days and forcing many residents to evacuate their homes.

It was not clear if Ms Simpson's hike at the Mount Aspiring National Park was affected by the rains.

Media reports said Ms Simpson is from Essex in Britain and her parents are flying to New Zealand to help with the search.

Thousands of hikers visit New Zealand each year to explore its mountains and wildlife.

In 2016, a Czech women spent nearly a month alone in a warden's hut on a remote hiking trail on South Island after her male partner was killed in a fall.

Questions were raised last year about New Zealand's reputation as a safe, easy-going holiday destination after a 22-year-old British woman backpacker was murdered by a man she met on dating app Tinder.

A jury convicted the man in November and he is to be sentenced on Feb 21.