Actress Jennifer Garner has sparked rumours she is expecting her fourth child with husband Ben Affleck after showing off what appears to be a baby bump in new pictures.

The Dallas Buyers Club star was photographed on two separate occasions in July (14) sporting a visible bulge under her shirt and dress, according to the New York Daily News.

Garner and Affleck, who wed in 2005, are parents to daughters Violet and Seraphina and son Samuel.

The couple has yet to comment on the rumours.