The man accused of murdering Emma Faulds denied she was "lying dead" in his home as he chatted to his mother.
Ross Willox was quizzed by detectives probing the death of the 39 year-old.
The 41 year-old claimed he only knew there was any concern about Emma when her sister Sarah called him.
Willox went on to refute the suggestion she "died" in his house.
He is accused of murdering Emma at his home in Fairfield Park, Monkton, Ayrshire, on April 28, 2019 by means unknown and then dumping her body.
Jurors at the High Court in Glasgow today heard his police interview, which took place on May 9 2019.
The trial heard claims Emma had gone to Willox's home on the night of the alleged killing.
They were then said to have later gone to Emma's, she had wanted to "continue partying", but Willox eventually left the next morning.
Willox told police he then went to bed and time became "non-existent".
The court has been told Emma was reported missing on April 30 by her parents.
During his interview, Detective Inspector Stephen Tennant asked Willox when he first learned of any concern about Emma.
He replied: "Her sister Sarah contacted me and asked had I seen or was Emma still with me. I said no.
"She told me her phone was not on. I tried, but it went straight to answer machine.
"Sarah said she was worried and that she had not heard from her."
Willox added he "did not know anything" to tell Emma's sister about where she may be.
The court heard how news soon spread of Emma's disappearance and the hunt to find her.
DI Tennant probed Willox on what he did to help.
He put to him: "So, your friend went missing. You have known her for 18 years, see her regular.
"When she goes missing, you do not get involved to help find her?"
Willox: "I was not informed that there was a search."
Willox added he had not watched any news reporting the disappearance.
He said at one stage: "My mind boggled and has been for as long as its been going on."
Willox told police his mum had visited after he claimed he returned from Emma's.
DI Tennant: "Was Emma dead in your home when your mum attended?
"Did you put your mum in that position?"
Willox: "No...no."
The detective: "Was Emma lying dead or injured in your house when your mum was there?"
Willox again denied the accusation.
He was further quizzed on the purchase of four bottles of Domestos bleach and rubber gloves from a Poundstretchers store after the alleged killing.
He replied: "That is to clean my decking."
Willox denies the charges.
The trial, before judge Lord Mulholland, continues.
