The actress was filming the sequences for The Counselor on the bonnet of a yellow Ferrari at Stoke Park golf course, Buckinghamshire with Javier Bardem.
A source told The Sun: "It was like a military operation.
"Producers had thought of everything to stop any intruders possibly getting a glimpse."
It was reported that an ex-SAS squad and dog unit were positioned around the golf course and in the trees to make sure passers-by or fans could not see what was going on.
Modesty screens were also put up ready for the midnight shoot on Tuesday (September 11).