Soulja Boy's sitting in a jail cell, but even from there he can smell something fishy back at his house -- and it's that $500k burglary ... which he's now convinced was pulled off by someone close to him.
Sources close to the rapper tell TMZ ... peeps on his team have analyzed the home surveillance and say there's evidence the burglars had some inside information because they knew when to strike, where to enter the house and beelined it straight for his safe.
Crooks - Soulja - Boy - Crib - San
As we first told you ... the crooks hit Soulja Boy's crib in the San Fernando Valley after he was locked up on a probation violation earlier this month. They made off with jewelry, cash and his iPhone -- which they promptly used to go live...