Camera shows Lohan about to inject herself in the past

Lindsay Lohan has been caught on camera about to inject herself with what appears to be heroin.

The troubled actress - who was sentenced to four weeks in jail on Friday for violating her probation by failing two drug tests, but was released hours later - is photographed wrapping what looks like a tourniquet around her arm to raise a vein before hovering a syringe over her left arm.