One of the men charged with the murder of an Oamaru farm worker has told a court he was fearful of a fellow accused.

Steven Boskell, Robert Cummings and brothers Jacob and Ryan Geary-Smart are on trial in the High Court at Dunedin for the murder of Justin McFarlane.

The first defence witness called is Boskell and he's been describing the weeks leading up to the death of Mr McFarlane.

He described animosity between himself and Cummings over drugs as well as hearing threats against him.

"I didn't really want to be around him when it's just me and him.

"From what I've seen of him, he's a bit loose and after those texts, him texting Ryan...

"I didn't really want to be around him by myself."