Officers say a group of thugs broke in to the site office and stole keys to the plot houses, which were accessed and “extensively vandalised.”
The incident happened some time between 3pm on Friday, April 26th and 8am on Monday, April 29th at the Lovell Homes site in Scott Road.
Various power tools were also stolen from the office and police inquiries are ongoing to identify the culprits.
Constable Kirsten Young, of Broxburn Police Station, said: “The developers are obviously incredibly frustrated and disappointed that many of their recently built homes have been targeted and now require considerable repair.
“We believe that this damage has been caused by a group of people and would urge anyone who remembers seeing anyone acting suspiciously in the area over the weekend to contact police immediately.
“Likewise, if you have any other information that you think is relevant to this investigation then please also get in touch.”
Those with information can contact Broxburn Police Station via 101 and quote incident number 0637 of the 29th April. Alternatively, an anonymous report can be made to the charity Crimestoppers on 0800 555 111.
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