Prince William and PM John Key at the BBQ. Pic: NZPA

Wellington, Jan 19 NZPA - Prince William wraps up his three-day visit to New Zealand with a visit to Wellington Hospital this morning as police investigate a security breach at a barbeque held in his honour at Premier House last night.

Police are consider laying charges after a radio station employee jumped a fence with a packet of sizzlers sausages to join the party. Warwick Slow, 19, an employee of radio station X105, told The Dominion Post he'd been turned away from the main gate about 7pm, so jumped a fence about 50 metres down the road and walked up the driveway at Premier House in Thorndon.

He made it to the barbecue and band area, mingling with guests for several minutes while on his cellphone to the radio station's host Iain Stables, and the stunt was broadcast on air.

Police noticed him after about five minutes and Slow was taken to a basement, questioned and searched.

Prince William had not yet arrived when Slow made his entrance to the party.

A spokesman for the prince said the incident was now in the hands of the police, who were investigating whether to lay charges.

It was the second incident of the day for police, after a man was arrested outside the new Supreme Court, which Prince William opened yesterday.

The man, who was protesting about the Family Court, was shouting obscenities near Prime Minister John Key and ignored police warnings to tone down his language, Inspector Greg Gilpin said.

Mr Gilpin said there was "a bit of a scuffle" as the man was arrested, and the protester received a cut to his face.

Arriving in Auckland on Sunday, Prince William touched down in the capital yesterday morning after a 20 minute delay due to fog at Wellington Airport.

He was taken to the National War Memorial where he laid a single rose on the Grave of the Unknown Soldier.

He inspected a tri-service guard of honour and laid a large poppy wreath in the War Memorial.

From the War memorial it was off to the Supreme Court opening where he was greeted by around 4000 people, including several groups of protesters, including Ministry of Justice employees, and Republican Movement members who unfurled a banner outside the Court stating "It's time for a republic."

During the opening Prince William expressed concern for the people of quake-devastated Haiti, but avoided the issue of republicanism.

The opening was the prince's first official duty on behalf of the Queen, and some media had speculated that he would use the occasion to say the British royal family would serve New Zealand as long as wanted.

The Supreme Court replaces the London-based Privy Council.

Then it was back to nature for the prince who was taken for a visit to Kapiti Island, a bird sanctuary off the Kapiti Coast about 50km north of Wellington.

Accompanied by Prime Minister John Key, local MP Nathan Guy and Associate Conservation Minister Kate Wilkinson, the prince, dressed casually, arrived about 3.30pm, and representatives of local iwi Ngati Toa Rangaiti welcomed him with a mihi.

He got the chance to hold a spotted kiwi -- one of over 1200 on the island, according to DOC ranger David Wrightson.

Joking with photographers, and holding the moulting kiwi, he told them: "This is my date with a kiwi."

Prince William will visit children at the new Wellington Hospital this morning before flying to Sydney later today.