Kourtney Kardashian's Calabasas home was robbed of $50,000 in cash, TMZ reports. Sources said the robbery took place shortly after Khloe Kardashian and Lamar Odom's old Tarzana mansion was burglarized. Police believe the two thefts were not a coincidence and are connected.

"Giving the timing and the fact that Kourtney and Khloe work with so many of the same people, we're told police believe the two thefts are connected," TMZ writes.

Reportedly police plan on questioning people who had access to Kourtney's home around the time of the robbery. They will pay close attention to the ones who also had access to Khloe's.

According to the site, the money - which was given to Kourtney after an appearance gig - was safely hidden inside her house. Source said when she returned a few days later to deposit the money, it was gone. Cops didn't find any signs of forced entry in either theft case, sparking belief that it could have been an inside job.

Khloe is so convinced that the person who stole $250,000 worth of items from her home is someone she knows, that she's demanding that everyone who had access to her house to take a lie detector test and submit fingerprints.

Only a handful of people had access to the home, which has been vacant for a month, including house staff, movers, inspectors, assistants, film crew and Khloe's soon-to-be ex-husband Lamar Odom.

However, sources told TMZ that she doesn't suspect Odom because he's in Spain playing basketball.

"The house sat empty and only she and Lamar and her staff had access to it while it was vacant," a source told Hollywood Life. "Lamar never went there and has been with his family for months and now he's not even in the country so she thinks someone that's close to her stole her things and thought she wouldn't notice. It's really f**ked up and she's going to get even."