Two uniformed police officers from the States of Jersey Police shift glumly from foot to foot at the entrance of the former care home while blue police tape twists and billows in the wind on a neighbouring fence. Off-duty and dozing contentedly in the back of a white van are the two police dogs tasked with helping locate traces of human remains.

The low-key police presence at the site belies the enormity of the investigation that is being headed by Jersey's Deputy Police Chief Lenny Harper into years of alleged serial child abuse and the potential murder of a child.

Behind the doors of this house of horrors forensic teams, archaeologists and anthropologists are on their hands and knees sifting painstakingly through dust and debris in a bid to uncover the truth of what really happened here.

Jumping out of the car Mr Harper looks slightly distracted as he strides towards the building, but a few minutes later he can be heard chuckling with someone before bounding unceremoniously into a dimly lit sitting room towards the front of the house.

"Oh, I feel uncomfortable getting my picture taken," he says with an unmistakable North West twang when asked if he would be happy posing for a photograph.

This is the man who confidently faced the world's media, answering unscripted questions on live television, who fearlessly took on " corrupt cops", rooting them out of the force and defiantly stood his ground when faced with opposition by some Jersey politicians who disliked his openness with the Press about the investigation.

"I can stand in front of 100 reporters answering questions for two hours but I really do feel uncomfortable standing for a photograph. It's funny isn't it?"

After more than 30 years in the police Lenny Harper has a long and impressive career record.

In 1971 he left his family home in Londonderry ("I'm from Londonderry and my wife is from Derry" he chuckles later as he talks about his mixed marriage) to join the RAF police aged 19.

He had applied three times to join the RUC but at just under 5'8'' tall he was a quarter of an inch too short.

"I really wanted to join the RUC but I never seemed to grow," he says.

In 1974 he joined the Metropolitan Police, progressing to the rank of Detective Inspector and eventually heading the divisional crime squad in Peckham. He was also seconded to the RUC for several months as Detective Sergeant during the height of the Troubles.

Before transferring to Jersey in 2002 he was working as Chief Inspector with Strathclyde Police, where he spent a year as Deputy Commander of Glasgow.

He says he decided to transfer to Jersey because he wanted to "get back to operational policing", but with low crime rates on the 12 mile long, six mile wide island, another consideration must have been the chance to finish out his career at a slower pace?

"Yeah, it is a very crime-free environment and the quality of life is fantastic - a bit like Northern Ireland but with the sunshine. It was an ideal opportunity from a work point of view and from the quality of life point of view."

But that longed-for relaxed pace of life did not last long when he became the subject of a campaign of intimidation when trying to root out corrupt police officers from the force.

"Like any other police force we have had some bad eggs to deal with over the last four or five years and we have dealt with them. A few tried to make my life difficult in relation to that investigation.

"I received threats to burn my house down, fire bomb my car. We stepped up security for a bit but I wasn't that worried. My wife was a bit concerned but she has been through worse."

However, it was the uncovering of what is now potentially one of the UK's biggest child abuse cases, with more than 100 people claiming to have been assaulted at Haut de la Garenne since the 1960s, and later the discovery of the partial remains of a child on the site, that launched Mr Harper back into the heart of a major police investigation.

"I had been involved in child abuse investigations before but never anything on this scale. Very few jobs of this scale have arisen anywhere.

"I couldn't have imagined anything on this scale. It has happened in one of the most unlikely of places, but it has happened all over the world and in many different institutions, so in hindsight it shouldn't have been that surprising."

Behind the musty living room where we are sitting, buried under an old stairwell, the partial remains of the unidentified child were discovered on February 23. Pausing by the excavated, airless spot I am filled with a morbid curiosity as to what might have happened here.

"When victims began coming forward and telling us they believed remains were buried on the site our overriding wish from the outset was that we wouldn't find anything.

"But we found the skull bone of a child and other bones since, which we are still awaiting tests on.

"We always felt that if there was something to be found then we wanted to find it but at the same time we really didn't want anything to be found because it meant something horrible may have happened here," he added.

At this stage of the investigation it is still unclear when, how or why the child died. Until forensic investigations are complete the main enquiry remains the child abuse investigation which has 160 alleged victims - not all from Haut de la Garenne - and stems as far back as the 1940s to as recently as 2003/04. There are 50 plus suspects - the majority of whom are still living in Jersey.

So far one man, Gordon Claude Wateridge, has been arrested and charged with indecently assaulting girls at the home where he was a warden.

"We haven't arrested or questioned any others yet for the simple reason that we want to make sure we do things properly. The credibility of the investigation is vital. We need to be sure that when we move in on suspects we have all the evidence we need. There will be other arrests. I can state that without fear of contradiction," said Mr Harper, who is refreshingly open about progress in the investigation.

Although he is due to retire in September (when he will embark on a trip to Italy with his wife before moving to Scotland to be close to his two daughters and grandchildren) Mr Harper is adamant he will have seen most of the investigation through.

"By the time I retire there will be a number of people arrested, charged and ready for prosecution. We are getting there. I think undoubtedly I will be leaving before it is completely finished but a huge percentage of the work should be done by then I would hope."

Mr Harper's mobile begins to buzz incessantly and a camera crew from Panorama are waiting for an interview, but he is keen to talk about " back home" before I leave.

"We go back home all the time. I can't get over how much Belfast and my own town have changed. It is great," he says.

When I point out that our interview has run well over time he adds: " Panorama can wait. The Belfast Telegraph comes first."