A fortnight ago an amateur photographer who made the discovery and a BBC Scotland film crew covering his story walked around the former hospital unchallenged.

But Gazette photographer Lindsay Addison was repeatedly intercepted when we recently tested NHS Lanarkshire's claims of tightened security on the site.

Although not physically thrown off the site, he was firmly told his presence was unwelcome.

And he was forbidden from re-entering the buildings where the old medical files and x-rays had been abandoned when NHS Lanarkshire closed the hospital seven years ago.

The health authority denied that it was about to spend hundreds of thousands of pounds of public money fencing off the huge site completely.

And it undertook to look into Gazette queries about any dangerous materials, such as asbestos, on the site which could be harmful to anyone wandering the abandoned complex.

The authority also explained it was still in ownership of the site — despite it commonly being believed that it had sold the land for millions to a private housing developer years ago.

A spokesman for NHS Lanarkshire told the Gazette that it had, indeed, sent a team of security contractors onto the site following the discovery of the confidential materials.

However, he said he thought it unlikely that a total, expensive sealing off of the site with security fencing would take place.

"It really is a vast site and would be very difficult and expensive to totally fence off," he said.

He pointed out that the site, despite being written off as a general hospital in 2001 to be replaced by Wishaw General, still retained NHS Lanarkshire offices in what was the old Palm Court nurses accommodation.

This was converted for office use by the health authority due to a shortage of administration accommodation in central Lanarkshire.

The same building also contains a public health and information library so, said the spokesman, some public access to the site had to be maintained.

The health authority was considering putting temporary, portable security fencing of the sort used on building sites around individual abandoned buildings.

As to unconfirmed reports that vandalism to some of the old buildings had exposed potentially dangerous 1940s and 50s building materials such as asbestos, he said it would be looked into.

The spokesman added that, in any case, it was unsafe to go into any abandoned building — especially those which have lain unmaintained for so long.

He said: "We really have to depend on people using their common sense to realise that entering any abandoned building is potentially dangerous.

''Given the age of the Law buildings, it is probable that materials like asbestos were used and we will be investigating that further."

He said that the site was still in Lanarkshire NHS ownership despite widespread public belief that it had been sold off some years ago.

He added: "We are still in the final stages of negotiations over the sale of the site."

Work on a huge housing development on the site was held up some years ago by a Public Inquiry being called into the issues surrounding such a large influx of new residents to the Law area.

It included the provision by the developers of a re-opened Law Station and upgrades of the local public and sewage services.