Jury out in WA 'threesome' murder trial

A jury has begun deliberating in the case of a former fly-in fly-out worker accused of murdering a man who had a "threesome" with his girlfriend.

Ryan Christopher Hawke has been on trial in the West Australian Supreme Court since June 17, charged with murdering Mark Koller, 50, at the Crystal Brook Caravan Park in Orange Grove in April last year.

Hawke admitted stabbing Mr Koller but claimed he expected the confrontation would only be a fist fight and brought a knife with him to defend himself.