AusQuest (ASX:AQD) started the third-stage reverse circulation drilling program covering 6,000 meters at its Cangallo discovery in Peru, according to a Tuesday filing with the Australian bourse.

The program is designed to expand the copper and gold mineralization to the south of the current drill coverage, with results to be used to prioritize deep diamond drilling, the filing said.

The program is anticipated to take about four to six weeks, with final assays expected within four weeks after completion, per the filing.

Shares fell 5% in afternoon trade Tuesday.