The trial of Stephen McKinney heard today (Monday) of his own frantic attempts to save the young wife he is accused of murdering during their family boating holiday four years ago.

Dungannon Crown Court was told the 44-year-old father of two had immediately jumped into Lough Erne, initially managing to grab hold of her, but when he lost his grip had searched for her underwater.

The jury of eight men and four women also heard that McKinney blamed himself for what happened and had shouted to his lost wife: "Lu Na, Lu Na, Lu Na, it's my fault".

Initially when asked by a detective what had happened, he reportedly told her: "I'm trying to get a slow motion picture of it."

McKinney, originally from Strabane, who lived with his family in Convoy, Co Donegal, but now with an address in Castletown Square, Fintona, Tyrone, denies her murder.

The detective said they'd talked a short time after 3am on April 13, 2017,when McKinney had just told his children their 35-year-old mother Lu Na was dead.

This was in Enniskillen's South West Acute hospital where first Mrs. McKinney was rushed in one ambulance from the shores of Lough Erne, followed by her husband and children in a second ambulance.

McKinney reportedly told the officer the boating holiday was "a treat for the kids" and also an early celebration of the couple's up and coming 14th wedding anniversary. He said both his wife and daughter suffered from travel sickness so they hadn't gone far before mooring at the western jetty at Devenish Island for the evening.

He described how after the children went to bed he and Lu Na shared some beers, and that she had also taken a sleeping tablet. They talked about home improvements before turning in themselves about an hour or so later.

Lu Na, he said complained about the boat ropes but that they both dozed off, before she woke him saying the boat was moving. McKinney said his wife by this time had her coat on and he told her to "give me a minute... I need a cigarette" and that he'd just put the cigarette in his mouth when she went out the door.

He followed, "only a second behind her", and although dark outside, the moon was bright. Lu Na, he said, didn't appear to walk off the back of the holiday cruiser, but "fell in sideways" and when she fell in "shouted 'help'".

"I jumped in straight away," he told the detective, telling her of grabbing his wife by the arm of her black furry jacket, and was trying to hold her up while also holding on to the boat.

However, she kept pulling him down, and he lost his grip: "I tried to look under the water for her... but she was gone".

McKinney said he could not remember how long they were in the water, "one minute or ten" and while he'd initially shouted her to stop pulling him down, he was then "shouting Lu Na, Lu Na, Lu Na it's my fault".

The detective said McKinney told him having got back on the boat he tried to spot his wife in the water using a torch, but couldn't before raising the alarm. He said when police arrived at the scene he "kept shouting, I think she's over here".

McKinney also admitted to the detective, one of the sleeping tablet she'd taken, were bought online and that she's "used them once or twice before" but that he didn't know why she had not gone to her own doctor for them.

Eleven days later the detective said McKinney had called her and when asked how he was sleeping, broke down, telling her it was "very difficult".

Later when questioned about the sleeping pills he "became very emotional" and asked the detective: "Am I in trouble about this... do I need to arrange something for the children ... I know I should not have bought them".