Kim & Khloe Kardashian Call Amy Bradley's Mom to Brainstorm About Search

Kim and Khloe Kardashian are stepping in on a real-life mystery -- TMZ has learned they called Amy Bradley’s family to help track her down.

Sources tell TMZ Kim and Khloe personally called Amy’s mom, Iva, last Thursday -- chatting for about an hour as Iva filled them in on the case and where things stand now.

ICYDK, Amy’s family reached out after Kim posted about the new Netflix doc "Amy Bradley Is Missing" -- and we’re told Kim and Khloe were especially intrigued by the detail about an IP address in Barbados that kept checking the Amy Bradley Is Missing website.

It raises eyebrows, because whoever was behind it seemed way too interested in old family photos ... even pics of Amy’s car.

We’re told no cameras were rolling, and the call was totally genuine -- the Kardashians were really there to listen and brainstorm on how they could help.

Amy vanished from a Caribbean cruise with her parents back in March 1998 as the ship was docking in Curacao -- and her brother Brad told us recently the family has a gut feeling she’s still alive ... plus they’ve been swamped with new tips since the doc dropped.