A Douglas woman cleared of murder but found guilty of manslaughter has been told she can expect a substantial term in prison when she is sentenced on Thursday morning.

A jury of four women and eight men took 90 minutes to convict 26 year-old Arizona Devine Watterson on the lesser charge, after a trial lasting just over two weeks.

Acting Deemster Turner explained to the jurors that in order to find her guilty of manslaughter they needed to be sure she had intended to harm Billy Rogers, also 28.

The defence had claimed Mr Rogers received a fatal stab wound to the heart when he stumbled onto a ceremonial dagger while the pair were play-fighting, in Watterson's flat in March last year.

The prosecution insisted she had intended to kill him.

Watterson could be seen crying in the dock as the verdicts were read out and Acting Deemster Turner told Mr Rogers' parents he seemed 'a lovely lad'.

Sentencing will be at Douglas courthouse from 9.30am on Thursday.