Investigation examining the £1 sale of the toxic former Ravenscraig Hospital site has been passed to a specialist division

Officers on the force's Economic Crime Unit are poring over a large catalogue of documents — including Tele articles on the matter spanning nearly two years — as the probe widens.

A source confirmed that the unit — based at the Scottish Crime Campus at Gartcosh, North Lanarkshire — is now taking the central role in the investigation.

The insider said: "The enquiry has been passed to the Economic Crime Unit.

"As part of the enquiry they have taken the documentation to evaluate it and work out what they need to forward the enquiry."

A second source also confirmed that the inquiry had moved to Gartcosh.

We revealed in March that detectives based in Paisley had launched a probe into allegations surrounding land issues at the previously publicly owned Ravenscraig site.

It was secretly sold to social housing provider, and private company, Link Group Ltd for £1 in a so-called back-to-back deal involving NHS Greater Glasgow and Clyde and the Scottish Government.

The sprawling 83-acre estate — which has confirmed 'multiple exceedances' of dangerous and cancer-causing pollutants — was never placed on the open market.

The CID intervention in the matter came a year after councillors approved contentious plans from Link — which is affiliated to Larkfield Housing Association — to build 198 social homes directly on top of the harmful chemicals.

Several concerned members of the public have given statements to police and provided the comprehensive catalogue of documentary evidence which is now being looked into.

One police informant today welcomed the latest development in the investigation.

The person said: "I'm pleased that the police are taking this matter so seriously.

"When you have a situation where public land is sold to a private company for £1 without ever being placed on the open market it has to be looked into properly."

The Scottish Government — whose More Homes arm helped facilitate the £1 land sale — is primed to release grant funding totalling £15.3m to Link for developing the polluted site.

The land deal — concluded three years ago — was subsequently described as a 'disgrace and a scandal' by former Provost Ciano Rebecchi, who said he had seen documentation which pointed to the hospital and its grounds being valued at £15 million.

Campaigners against Link's plans have said that a full investigation is needed into how NHS ground 'found its way into a non-public sector asset hold without entering the open market'.

Inverclyde Planning Board — whose convener David Wilson is a former Link director — voted 5-4 to approve the company's plans for Ravenscraig on March 6 last year.

The decision was made after Councillor Wilson — who remained a director of Larkfield Housing Association — declared an interest and took no part in the debate or vote.

We told just a week earlier that levels of contamination on the site were eight-times above officially recognised acceptable maximums.

Link's solution for the contamination — which has been approved by Inverclyde Council — is to leave it where it is and use 'capping layers', and the housing development itself, as barriers between people and the pollutants.

Following Telegraph coverage of Ravenscraig — and an admission by Link that it made an untrue claim that the pollutants couldn't spread — a councillor who voted for the housing development said he would now be opposed to it.

Colin Jackson spoke out after globally respected contamination expert Professor Andrew Watterson debunked Link's assertion that the contaminants were 'not leachable, or soluble and will not migrate horizontally'.

The professor also said that capping layers placed on top of the pollutants will ultimately fail.

Councillor Jackson's u-turn would have reversed the planning approval given for the development, however, council officials rebuffed a call from SNP group leader Chris McEleny for a 'full review' of the Ravenscraig matter.

The Scottish Government has previously said that it can't comment on a live police inquiry.

But a government spokesman did say: "The transfer of this land from the Scottish Government More Homes Division to Link was carried out in accordance with all due process."

A Police Scotland spokesperson said: "We can confirm that information has been passed to Police Scotland regarding land at the former Ravenscraig Hospital in Greenock. Police enquiries into this matter are at an early stage."