The Metropolitan Police is continuing to investigate incidents of deliberate contamination of Allied Bakeries’ Kingsmill bread, produced at its Orpington plant in Kent.

A total of 35 complaints of contamination were made by customers between February 2005 and January 2006. The final one, on January 25, was of fragments of glass in Kingsmill bread. Several incidents of contamination have been ruled out as unconnected to the main case, a spokeswoman said.

She said a large number of staff had agreed to give samples of DNA and fingerprints to police, and this screening has now been completed. Enquiries are ongoing.

Allied Bakeries said in a statement that, as the police investigation remains ongoing, it would be inappropriate to comment fully at this stage. However it introduced tamper-evident packaging on Kingsmill products earlier last month. The packaging has a modified seal, which means it is easier to see if the bag has been tampered with or not.