ITV News understands that Wiltshire Police are searching the garden of murderer Christopher Halliwell's former home in Swindon.
Two properties, believed to be on the same street, are being searched.
The operation is expected to last a couple of days.
Police say it's intelligence led, based on new information, and they emphasise they are not sure if they'll find anything.
Police have never searched the exterior of the property before and say that the search is unrelated to the current owners.
Halliwell, a Swindon taxi driver, was jailed for a whole life term, after being found guilty of murdering Becky Godden.
The 52 year-old was already serving a life sentence for the murder of Sian O’Callaghan in 2011.