BANGOR – Two former executives of a Winslow biological laboratory pleaded not guilty Monday in federal court to charges that they were involved in a scheme to smuggle a chicken virus into the country from Saudi Arabia so they could produce a vaccine.

A third person charged in connection with the scheme pleaded not guilty in Bangor last week.

Dennis Guerrette, 40, of Brunswick, former chief financial officer of Maine Biological Laboratories; Thomas Swiecz-kowski, 47, of Vassalboro, former vice president of production; and Marjorie Evans, 41, of Belgrade Lakes, former vice president of quality assurance and regulatory affairs, were indicted by a grand jury last month in U.S. District Court in Portland.

Guerette and Swieczkowski each pleaded not guilty Monday in Bangor to conspiracy to commit mail fraud, concealing smuggled items, making false statements, violating the Virus-Serum-Toxin Act, being an accessory after the fact of smuggling and three counts of mail fraud and aiding and abetting mail fraud.

Evans pleaded not guilty Dec. 30 to two counts of making false statements and aiding and abetting a violation of the Virus-Serum-Toxin Act, in addition to the same five counts her co-defendants are charged with.

If found guilty, Guerrette and Swieczkowski each could face up to 671/2 years in prison and more than $1.1 million in fines. Evans would face up to 781/2 years in prison and more than $1.7 million in fines.

Trial dates have not been set.

Two former lab workers pleaded guilty to their part in the scheme in November. Walter Gogan, 63, of Winslow faces up to 21/2 years in prison, and Peggy Lancaster, 47, of Mount Vernon faces up to a year in prison.

Gogan pleaded guilty to being an accessory after the fact to smuggling the virus into the country, and Lancaster pleaded guilty to directing employees to place incorrect labels on vaccines.

Sentencing dates have not been set.

The case dates to 1998, when a Maine Biological customer in Saudi Arabia discovered one of its chicken flocks had avian influenza, according to the indictment. To produce a vaccine, Maine Biological required a sample of the virus, which was then smuggled into the United States, according to prosecutors

After producing a vaccine, company officials allegedly falsified production records and shipping documents to send it to the Saudi customer.

The Associated Press contributed to this report.