Capt. Haseeb Hosein, who has commanded the Area B-3 police district in Dorchester and Mattapan since 2014, was placed on paid leave on Monday amid a BPD anti-corruption investigation.

The acting commander at B-3 is Capt. James Fitzpatrick, according to Sgt. John Boyle, a BPD spokesman.

"It’s an active investigation, it’s an open investigation, and it’s an anti-corruption investigation," said BPD Commissioner William Gross, who said he could not comment further on the details on the probe, which is being led by the BPD's own Bureau of Internal Affairs.

Hosein was the third person of color appointed to a district command by BPD Commissioner William Evans in October 2014. He is a 29-year veteran of the department and a Dorchester resident. He is also the first Muslim-American appointed to a police command in Boston.