Rapper Lil B is furious $10,000 went missing from his hotel room -- and he's pointing the finger at the hotel staff ... after management gave him the boot for hotboxing the place.
Lil B tells TMZ he was staying at the Oakland Airport's Red Lion on Tuesday when the hotel kicked him out because guests were complaining about marijuana smoke coming out of his room.
The rapper claims hotel management told him security had entered his room while he was gone ... found a small bag of pot, and then asked him to leave.
When Lil B went back to his room to collect his things, he says he noticed $10,000 cash was missing. He went to the front desk to file a theft report, but claims the employee ignored him. He recorded that awkward encounter and posted it online. He also blasted the hotel staff on Twitter.
Since the hotel wasn't helping ... B says he went to Oakland PD to file a report. Cops tell us they are "still in the process of verifying if this incident occurred."
We reached out to the Red Lion Hotel for comment ... so far, no word back.