The new figure is more than treble what it cost to look after the venues a year ago.
In 2011 the has government spent £35m protecting the sites, and in September alone they cost £7.5m to protect.
The money is being spent on security guards, fencing and screening people going in and out of venues.
With less than 250 days until the Games begin, work in the nine venues is nearly finished.
The five arenas that have been completed are the Olympic Stadium, Aquatics Centre, Velodrome, Handball and Basketball Arenas.
Workers have now moved to finish the surrounding area.
There are plans for the Olympic Park Pleasure Gardens outside the stadium, which will hold cultural evens in the south of the park.
Organisers expect the Olympic Park to be a top tourist destination after the Games.
The Olympic Park Legacy Company has predicted that 9.3 million visitors from the UK and abroad will visit the park every year from 2016.
The site will also be used for corporate hospitality, weddings and filming.