A doting dad, who was wrongly accused of threatening to kill his former girlfriend in a row over their young daughter, today spoke of his year of "mental torture".

Simon Preston, 29, feared he would lose contact with his young daughter if he was convicted and given a long prison sentence. But yesterday a jury at Leeds Crown Court took less than half-an-hour to find him not guilty of the threat to kill charge.

Mr Preston has made an official complaint about how police handled the case and vowed to fight "to the end" for justice.

After the case, he said: "I feel relieved the truth has come out. But I also feel aggrieved I have had to go through more than a year of mental torture."

Miss Street, 30, had claimed Mr Preston grabbed her neck and pushed her around his parents' garden when she went to collect their daughter, then four, after an access visit, two days before Christmas in 2006.

She alleged he pulled her face towards him, threatened to kill her and said she would be dead if she went to police. Miss Street claimed he was very angry and she was terrified and took the threats seriously. But Mr Preston, of Bramhope Road, Cleckheaton, told the court that although emotions were high, he did not swear or raise his voice.

Questioned by his barrister, Emma Downing, he said he did not threaten Miss Street and had no physical contact with her during the incident, in which she suffered no injuries.

He told the court: "If I had behaved in such a way I wouldn't have got to see my little girl, and that's all I wanted to do. She had spent a lot of time putting together a list of Christmas presents. I had bought them and desperately wanted to give them to her."

The prosecution then offered no evidence on two charges of assaulting police constables during Mr Preston's arrest, which he had denied, and formal verdicts of not guilty were returned.

Mr Preston had told the court he and Miss Street had a three-and-a-half year relationship which did not end amicably, and court proceedings were ongoing over access to their daughter, who is now five. Outside court, he said West Yorkshire Police's professional standards department was investigating an official complaint he had lodged last February.

Mr Preston claims police officers wrongly accused him of assaulting them, assaulted him during his arrest and failed to make house-to-house inquiries or take a statement from his mother, who was present during the incident.

The officer in charge of the case, PC Guy Shackleton, of Dewsbury CID, admitted to the court he had not instigated house-to-house inquiries.

Mr Preston said the not guilty verdict had not yet sunk in. "I have had more than a year of knowing I was innocent but thinking I was going to get a lengthy prison sentence. I had the mental torture of thinking I wasn't going to see my little girl and that she wouldn't want to know me if I had to go away for a while. I was so depressed about it all, I would stay in bed for three days, and I feared I would lose my house."

He said his new partner had been a tremendous support. "She has stood by me and helped me with my case," he said.

A spokesman for West Yorkshire Police's professional standards department confirmed they had received a complaint and were investigating.