Glasgow City Council’s environmental health teams have been investigating allegations that halal meat is being supplied by illegal sources to city food outlets.

In the biggest case to date, food safety officers seized 1000kg of meat from two halal butchers operating in the city.

The meat – which was believed to be lamb but couldn’t be verified because it had no labels – had been supplied by an unapproved cutting plant in Lancashire.

Halal meat involves slaughtering animals or poultry in a specific way. It is eaten by followers of Islam and is supplied by specialist butchers.

A report has been sent to the council’s Health and Social Care Police Development committee about traceability in the halal meat supply chain.

The report says officers launched a project in 2010 to find out if illegal meat was being processed in or distributed to Glasgow food outlets following allegations.

They found there was no evidence of meat being illegally slaughtered but documentation and labelling was “in many cases insufficient”.

The biggest haul happened in 2012. Recent allegations received include the supply of meat by unregistered traders, the supply of meat without any health marks and illegal street trading of meat from unmarked vans.

The report also referenced the horsemeat scandal in January 2013, which raised public awareness of the potential for food fraud in the meat supply chain.

The report said: “It would appear that some food businesses have not learned lessons from the horsemeat scandal.

“Unless traceability significantly improves it will continue to be impossible to differentiate legal meat from that originating from illegal sources.

“Consequently Glasgow food businesses remain at risk of food crime from elsewhere in the food chain.”

There are a total of 43 halal butchers across the city.