A POLICE officer who interviewed the father of Helen Munnings's child said the man had a ``perfect motive'' to kill the young Burnie mother, who has been missing since the winter of 2008.
Adam Taylor, 38, was the last known person to see Ms Munnings.
He gave evidence yesterday at an inquest into her suspected death.
Mr Taylor was in a de facto relationship with the mother of his two other children when he had a child with Ms Munnings, who was 20 when she disappeared three and a half years ago.
Their son is now five.
During a recorded interview with police the week after Ms Munnings disappeared, which the inquest watched yesterday, the officer said Mr Taylor had a perfect motive to kill her.
That was based on the fact that Ms Munnings was pregnant and threatening to tell people it was his child, and an ongoing attempt by her to break up his family.
Mr Taylor denied he killed her.
``She's the mother of my boy, I'd never want him to be without her,'' he said.
``I can see why you, adding those things together, might think that.''
At that stage in the interview, Mr Taylor said he felt faint, and lay down on the floor.
``I can't believe the way this is turning out,'' he said while he waited for a second police officer to fetch him a glass of water.
Yesterday, Mr Taylor was questioned by counsel representing the coroner, Simon Brown, about him being the father of the child she was pregnant with when she went missing.
A few weeks earlier, he had taken Ms Munnings to buy a pregnancy test and said she showed it to him after taking it.
``It was definitely positive,'' he said.
Mr Taylor said Ms Munnings told him that the father was from a one-night stand, but she threatened to tell everyone it was his.
He said he told her she should get an abortion because she could not look after herself or her son, let alone another child.
Mr Taylor was also pressed about conflicting statements to police about which route he took Ms Munnings for a drive on the day she disappeared.
His long-term partner at the time, Karalina Garwood, told police he had told her he had taken yet another route.
He will continue giving evidence today.