Khloe Kardashian, Lamar Odom's marriage in trouble as NBA star struggles with substance abuse

Lamar Odom has gone missing, TMZ are reporting.

The website claims that people close to the NBA star have been unable to find or contact him for the last 72 hours.

The reports come after it was alleged that his wife Khloe Kardashian threw him out of the house on Wednesday.

The reports come as Khloe lashed out on Twitter on Sunday going on an expletive filled rant.

In a rare move she tweeted: 'Really hard to sit here and listen to people talk s*** about my family! F*** you and shame on you! I'm too protective for this s***!'

The couple have been subject to persistent rumours that their marriage is in trouble after Lamar, 33, allegedly cheated on Khloe, 29, with two different women. 

But several sources have told TMZ the real reason behind their marriage crisis is that Khloe reportedly believes that her husband has a drug problem.

Earlier this week the Kardashian family allegedly staged an intervention to convince Lamar to return to rehab, but he refused, reports the gossip website.

Khloe urged Lamar in August 2012 to go to rehab and after he entered a San Diego facility she hired private investigators to make sure he didn't leave.

Lamar reportedly constantly threatened to leave the rehab clinic and Khloe visited several times to convince him to stay, but he left after three weeks, sources said.

Lamar, who won two championships with the Los Angeles Lakers, stayed clean and played well last season for the Los Angeles Clippers, but sources said he resumed using drugs after the season.

Khloe was convinced of recent reports of Lamar's infidelity, but feels his drug abuse has been the main problem, the website reported.

Neither Khloe nor Lamar has contacted a divorce lawyer.