Media playback is unsupported on your device Media caption Could this quiet residential street in Harlech be about to become world famous?

Tensions are simmering in the battle to be crowned the world's steepest street.

In the one corner, Baldwin Street in Dunedin, on New Zealand's south island, is defending its title with a confirmed gradient of 35% at its steepest.

But residents of Harlech are adamant that their challenger, Ffordd Pen Llech, near the town's famous castle in Snowdonia, is steeper at 36%.

Now, Dunedin mayor Dave Cull has stepped into the fray and said his town has seen off challengers before.

Measurements were taken at Fford Pen Llech, in Gwynedd, on Wednesday and sent to Guinness World Records.

Image caption Did Gwyn Headley, who is behind the bid for Ffordd Pen Llech, start the war of words?

Image copyright Hamish McNeilly/Stuff Image caption Tourists regularly visit the current record holder, Baldwin Street in Dunedin, New Zealand

Confirmation on whether a new record has been set will not be given until later in the month.

But with the ink on the record sheet barely dry, the war of words has begun.

In a tweet, New Zealand journalist Hamish McNeilly reported Mr Cull suggesting that even if Baldwin Street lost its title - which he doubted - all was not lost.

"If Wales turns out to have a steeper one we will just have to arrange one of our periodic earthquakes and tilt Baldwin a bit more," Mr Cull was quoted as saying.

But it could be argued that the fighting talk started on Welsh soil earlier this week when Gwyn Headley, who is behind the attempt, accused the Kiwis of cheating.

"We suspect they are steepening the street," he had said. "It may not be the only record they lose this year [referring to the Rugby World Cup in September]."

Image copyright Hamish McNeilly/Stuff Image caption Baldwin Street - it's steep - but is it steep enough to retain world title?

Image caption Harlech residents believe their street is steeper

Guinness World Records sets out a definition for the steepest street.

It is based on its maximum gradient over a ten metre span, comparing the vertical rise to the horizontal distance.

The street or road is also defined as a public thoroughfare that is commonly used by the public, who are able to drive vehicles across it.