Gardaí are investigating a death threat issued against Minister for Natural Resources Noel Dempsey.
The threat is believed to have been made in a telephone call to Mr Dempsey's office yesterday from a man claiming to support the Shell to Sea campaign.
The call came shortly after the minister criticised the group for its blockade of the gas terminal being built by Shell in Bellanaboy, Co Mayo.
Shell to Sea has distanced itself from the incident, which it has described as "utterly deplorable".
Asked about the matter in Dublin this morning, Mr Dempsey said he was worried about the threat, but would not be changing his support for the Corrib gas project.