Police say they have seized more than $1 million worth of drugs and arrested a fourth man as part of raids across the Hunter Valley on Tuesday.

Five properties were raided as part of a year-long investigation into the manufacture and supply of drugs in the Hunter Valley.

Police from Strike Force Raptor, the State Crime Command Gangs Squad and Central Hunter conducted the raids about 9.30am yesterday.

Officers executed search warrants at the Portland Street clubhouse of the Gladiators outlaw motorcycle club in Horseshoe Bend where they arrested one man, and properties at Largs, Rutherford, Dungog and Port Stephens.

Detective Inspector John Walke from the State Crime Command Gangs Squad said a fourth man, a 53-year-old from Tenambit, was arrested this morning.

Inspector Walke said the investigation was ongoing.

Central Hunter local area commander Superintendant Garry O’Dell said the supply of prohibited drugs was a big issue in the area.

“Certainly we’re talking about a significant quantity today, if we hadn’t intervened then these drugs would have become available to people in the community,” he said.

“They’re illegal drugs, we see lots of poor behaviour and crime connected to illegal drugs.

“I expect it to make a significant impact on drug supply in the area and hopefully improve the life of all people in the area.”