Julia Roberts tried to help her half-sister Nancy Motes

OHMYGOSSIP — Julia Roberts was devastated that that she couldn’t convince her half-sister Nancy Motes to enter rehab before her tragic drug overdose death in Los Angeles, Calif., on Feb. 9.

Motes, 37, was found dead Sunday in a bathtub at a Los Angeles home. Authorities recovered both prescription and non-prescription drugs.

“The sisters had a very complex relationship. They used to be very close when they were younger,” a source told RadarOnline.

“Julia tried in vain over the years, even in the last six months, to get Nancy to go to rehab. Nancy refused the offers and that is when she would often publicly lash out at Julia.

“It hurt Julia, but she knew her sister was battling addiction. The addiction to prescription drugs made Nancy a totally different person. There would be periods of sobriety and with that brought clarity.

“It would be during those moments that the sisters would reconnect. Sadly, of course, those times became less frequent before her death.”