Pregnant reality TV star Kourtney Kardashian has lost treasured jewelry after a thief raided her California home.

The socialite called police on Saturday after discovering her Calabasas townhouse had been broken into and ransacked while she was out dining with her boyfriend, Scott Disick, reports TMZ.com.

The couple, who are due to welcome their first child in December, discovered the burglar had taken a Cartier watch worth $30,000, several diamonds, Disick's Rolex timepiece as well vintage jewelry Kardashian's late father Robert left her.

See more photos of Kourtney Kardashian here!

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(This news article provided by World Entertainment News Network)