A policeman has been charged after allegedly discharging his firearm at a vehicle during a a breath-testing operation in the state's south.

The leading senior constable was charged with reckless conduct endangering serious injury and reckless conduct endangering life after the incident, which occurred at Grantville, near Phillip Island, on May 20 last year.

No one was injured in the incident and the policeman has been transferred to other duties, Victoria Police said.

He is expected to appear in the Latrobe Valley Magistrates Court on January 25.