A sign at the controversial Blackbrook Lane site in Bickley has been attacked for a second time this month.
Lead plot owner of the land Lesley Osborne said on Saturday night a new information post was doused in petrol and set on fire.
Today (March 24) Bromley Police received reports of the incident and a spokesman said officers are currently investigating.
Mr Osborne, 65, of Welling, added a previous sign was also damaged on March 6, explaining it was found sawn in half.
News Shopper reported earlier this month the architectural consultant, along with 17 other landowners, have filed a planning application that could see houses developed there.
The group has underlined recent changes to government planning framework that it claims should allow building work to go ahead.
Mr Osborne had told News Shopper: “We want to improve and enhance the area – we want to see it used for something worthwhile.”
But local MP Bob Neill said the alterations to Green Belt policy noted by landowners have been “misinterpreted” and some residents in the area have come out in opposition of proposals.
Hannah Edmonds, 77, of Timms Close, said: “There is a strong feeling here that nobody wants it (Blackbrook Lane) developed.
“It would just be ghastly. We have traffic problems here already. The trees have gone and we’re losing green space.
“I would like to see a recreational park.”