ARKADELPHIA, Ark. (AP) — Two former university professors in Arkansas pleaded not guilty to charges alleging that they were making methamphetamine in their school’s laboratories.

Bradley Rowland and Terry Bateman were chemistry professors at Henderson State University when they were arrested in November on a raft of meth-related charges. They pleaded not guilty to all of the charges during a hearing Tuesday in Clark County Circuit Court, the Arkansas Democrat-Gazette reported. Both defendants are free on bond.

Authorities began investigating in December 2018 after a university lawyer told the sheriff’s office that a faculty member believed two professors were involved in illegal activity. Bateman and Rowland were placed on administrative leave in October following a police investigation of a reported chemical odor in the campus science center.

A school spokeswoman, Tina Hall, said the two no longer work at the university.