Angelina Jolie would be expecting her fourth biological child, if rumours of her pregnancy are correct.

The actor was spotted wearing a tight black dress and blouse with a slightly visible baby bump which sparked off the rumours. She was photographed with three of her children at a farmer's market in Los Angeles.

Angelina Jolie and Brad Pitt are the parents of six children including three biological children. The couple already has three adopted children Maddox,10, Pax, 8, and Zahara, 6.

"Angelina is really savouring every moment. She's having a tough time with morning sickness but says it's all worth it," The Sun quoted a report in the US magazine OK! as saying.

"Angelina has cleared out her bedroom and redone it in white. She wants it to have a Zen-like feeling because she believes in the mind-body connection and wants her mind at peace," a source said, according to the report.