A vicar was forced to patrol her church in the dark after metal thieves threatened to return to remove more of its lead roof.

St Mary’s Church in Launton, near Bicester, was targeted on Sunday night.

Then on Wednesday night the thieves returned to loosen more lead in preparation for another raid.

The church has been targeted by metal thieves before and was landed with a £35,000 bill when lead was taken from its roof in March 2010.

But despite thousands spent on lights, alarms, a neighbourhood watch scheme and SmartWater, tightened security has not deterred the criminals.

And with the thieves likely to return, the church’s vicar the Rev Becky Mathew went out with a torch on Thursday to check the church throughout the night.

Mrs Mathew said: “We’ve got an alarm up there, we’ve got neighbourhood watch and we’ve got flood lighting so we’ve done what we can – but it’s a case of always saying to people to be vigilant.”

On Sunday the alarm was set off at 12.10am and 1am, alerting the church warden who could not see the damage because it was dark. The next morning 12 sections of lead were found to be missing as the rain poured down.

Mrs Mathew added: “Luckily there was no major water damage – just a few books.

“The local farmer came over with some tarpaulin and we managed to get it all ready for the Sunday service.”

Now the church is considering upgrading its security again – and using ‘lead-replacement’ roofing.

Mrs Mathew added: “I’m not going to lie awake at night worrying they might come back. If anything is going to keep me awake it’s the financial implications of this.”

SmartWater is a non- hazardous liquid which contains a forensic code, meaning marked items can be traced back to the owner. It is invisible under normal light, but glows under UV light.

Pc Caroline Brown said: “The church has done all it can. The roof was alarmed, they had treated the lead with SmartWater and they had special external lighting.

“The only thing I can suggest is if possible is to consider using a lead-replacement.”

North Oxfordshire MP Tony Baldry said the Legal Aid, Sentencing and Punishment of Offenders Bill which is going through Parliament could offer hope.

He said: “Stealing from a church is a despicable crime because one is stealing from the community and from the past and future generations.

“Parliament has created a criminal offence to prohibit cash payments for scrap metal which means payments will have to be made to a bank account to create a paper trail. Secondly we are significantly increasing fines for all the offences under the scrap metal dealers act.”

Call Pc Brown on 101 or Crimestoppers on 0800 555111 if you have any information.