Legal action may be taken against a company which installed a communications mast on a council block of flats without permission.

Brighton and Hove City Council has discovered the Tetra mast on Theobald House in Blackman Street has been operating for several weeks, despite assurances to the contrary from operators O2 Airwaves.

Council lawyers have given the firm until noon on Monday to switch off the mast. All equipment must be removed by August 31.

In a letter they tell the company their action amounts to trespass.

Property councillor Simon Burgess said: "We are very concerned to discover O2 Airwaves has switched on the Tetra mast it placed on Theobald House.

"The council did not give its consent as landlord to the mast being placed there. It was previously given assurances the mast had been switched off while the firm sought alternative sites.

"It is right in these circumstances the council commences legal action against O2 Airwaves."

Green convenor Keith Taylor, who represents the block of flats, said: "We are indebted to residents who told us of their suspicions the mast was operating illicitly. People have been complaining of sleeplessness and other conditions which goes to underline concerns over adverse health impacts.

"I am very pleased the council is now taking swift and effective legal action to remove this equipment.

"It uses technology which is largely untried and untested and certainly unwanted by the city centre residents I represent."