A shocking picture of a labourer balancing on a set of ladders at a Bushey building site has led council inspectors to issue a warning to the contractor.

Health and safety officials stepped in after a worried neighbour took photographs of a builder working three storeys up on an extension to a property, in Partridge Close.

Peter Ashworth, whose house in Merry Hill Road backs on to the property, contacted Hertsmere Borough Council and the government's Health and Safety Executive (HSE), on April 7.

Father-of-two Mr Ashworth said: "It was unbelievable, he was up there and the whole thing was shaking - he was having to grab hold of the roof. It was 50/50 whether or not he was going to fall. It was very scary - we wanted to shout to him to get down.

"He would have been lucky to survive a fall from that height. It was seriously bad judgement.

"If he'd fallen, he would have landed in our back garden. We have two young girls and that would not have been good."

Council inspectors visited the contractors, on April 11, to warn them about the misuse of ladders, though HSE officials only made it to the site this morning (April 18).

Mr Ashworth, 40, added: "If they have only sent someone down there today, that's pretty bad. It was very dangerous and if they're only going down there today, it's a bit off."

An HSE spokesperson refused to confirm whether an inspector had been sent to the site before today, adding that the department did not comment on ongoing investigations.

The incident also led planning inspectors to investigate the size of the Velux windows installed on the roof, after they were found to differ from the approved plans.

It is the second time the controversial extension has been put under the spotlight, after the developers were forced to re-apply for planning permission in March.

Neighbours complained that the "huge, barn-like" building was bigger than the original plans, which were approved by Hertsmere Borough Council in September 2008.

A retrospective application was subsequently approved by councillors, on March 24, despite protests from dozens of neighbours.