The total cost of erecting temporary, high security fencing at last month's G20 summit has been revealed.

According to a Canadian federal government spokesperson, fencing erected around the G20 security zone cost $9.4 million - almost double the original estimate.

Almost ten kilometres of temporary security fencing was put in place for the event, which attracted delegates from around the globe.

Public Works spokeswoman Natalie Pennefather said that the increase in cost from the original estimate of $5.4 million was the result of the event's security strategy being fleshed-out nearer the time.

Ensuring better traffic flow, lighting and ease of removal were all considerations that impacted on the final cost of the multi-million dollar high security fencing project.

The final sections of temporary security fencing erected at the G20 summit were dismantled at the end of last week, as downtown Toronto returned to normality.

Police in the city said that they would be investigating all criminal activity that took place during the event.ADNFCR-3337-ID-19880502-ADNFCR