Treetop protesters fighting to save an ancient wood have denied claims their campaign has turned nasty.

Suspicion was cast on the Titnore Woods campaigners when a digger belonging to landowner John Somerset was driven into a pond near their camp in Durrington, Worthing, last Thursday.

Yesterday, protester Sarah, 24, said: "It was nothing to do with us and we're upset about it.

"It's not the kind of thing we would do.

"We are here to protect the trees by living in them, nothing more than that.

"The pond the digger went into is a habitat for great crested newts and we wouldn't want to do anything to harm them."

The digger was still half-submerged in the pond yesterday and there were concerns about oil or hydraulic fluid, which had seeped into the water.

The campaigners said they did not know who had moved the vehicle and were asking residents if they had heard anything.

Sussex Police said it had no witnesses to the incident and no suspects.

Officers are examining the digger for forensic evidence.

A spokesman said: "The finger has been pointed at the protesters but if they are environmentalists it seems unlikely they would want to do that."

Campaigners moved into tree houses in the woods off Titnore Lane on May 28 and put up signs claiming squatters' rights.

They hope their actions will halt plans to chop down 210 trees to make way for a Tesco supermarket, 850 homes and a widened road.

Their peaceful campaign has won them the support of many residents who are also opposed to the proposals and who have been donating food to help the protest.

The campaigners living in their 20-metre-high camp have steadily grown in numbers. There are at least 20 of them at all times and yesterday work was being completed on an eighth treetop platform.

Sarah said: "The spirit in the camp is good and we're pleased with the way things are going.

"We have had lots of visits from residents and protesters who have joined us for a few nights.

"A lot of people came down from London at the weekend."

She said the camp had not yet received an eviction notice and would continue to expand.

The protesters are planning to hold an open day for visitors to come and see for themselves what the campaign is about.

Sarah said: "We won't be turning the campaign nasty or aggressive - that's not what we want."

The protest is the latest action by the Protect Our Woodland (POW) campaign, which has fought the development plans since 2002. The final decision on the scheme is expected next month