Like mother like son: Angelina and Knox's bonding on the balcony

When the cameras start rolling, she transforms into tough Interpol agent Cara Mason.

But as soon as filming for The Tourist stops, Angelina Jolie is straight back into the role she loves best - that of doting mum to six young children.

That much was evident as she spent time with her youngest son Knox during a break from work this week, as they shared a cuddle on the balcony of the 15th century Venetian palazzo where the family are currently staying.

The sheer joy on the Hollywood beauty's face shows just how much pleasure she takes from her maternal responsibilities.

Holding Knox in her arms, Angelina and her 20-month-old son - clutching a baby bottle - took in the view of the city together, the little boy clearly enjoying the experience.

And her proud mum was equally delighted to spend a few quiet moments with one of her twins, laughing along with Knox before planting a kiss on his cheek.

There was no sign of dad Brad Pitt, who has recently returned from a short stay in London, or the couple's other children, Maddox, eight, six-year-old Pax, Zahara, five, three-year-old Shiloh and Vivienne.

Just like their older biological sister, the twins have certainly inherited their parents' striking features – from Angelina's famous lips to their dad's blue eyes.

The family have been living in Venice since February while the Oscar-winning brunette is filming her latest project alongside Johnny Depp.

During Brad's British visit earlier in the week, he said that the brood were all enjoying being in the Italian city, describing their stay as "lovely".