Detectives seized Craig Meehan's computer from the home he shared with Karen Matthews on Moorside Road, Dewsbury, the day after Shannon went missing in February.

The nine-year-old was found 24 days after she vanished.

Yesterday David Holderness, prosecuting, told Dewsbury Magistrates' Court that Meehan faced charges which referred to 134 indecent images of children.

He said 133 of these were found on a second-hand computer that Meehan bought in 2006. The other was found on Meehan's mobile phone.

He denies all the charges.

Sixteen of the images have been classified as level four in a scale which runs from one to five and in which five is the most serious. The majority were classified as level one with others at level two and three.

Mr Holderness said Meehan had pointed the finger at other people. But the prosecutor said: "There are substantial amounts of material which, when put together, provide a convincing and overwhelming picture that it was Mr Meehan who was the person who downloaded the relevant materials."

Mr Holderness said part of the prosecution case would be matching the times at which the images were downloaded with fishmonger Meehan's work record.

Meehan, 22, faces 12 charges of possessing indecent images of children, which he denies.

The court heard how police seized the computer along with another from the house in Moorside Road on February 20, initially to help them with their search for Shannon.

Mr Holderness said it was only when the machine was thoroughly examined that the indecent images were found.

The prosecutor said Meehan bought the computer from the Brighthouse store in Dewsbury in September 2006.

He said it was second-hand but the firm had wiped it clean.

Mr Holderness said extensive inquiries had taken place and he was confident he could persuade the court "all of the images were not on the computer prior to the purchase by Mr Meehan".

He said that when detectives examined Meehan's computer, they found search words including "daughter" had been used.

The court heard how 16 of the images were classified as level four, 11 as level three, 19 as level two and 83 as level one. They are images of children believed to be aged between four and 16.

Mr Holderness told the court it was "extremely unlikely" that anyone other than Meehan was responsible.

"What the Crown would say was that the number of downloads when he's not at work make it extremely unlikely that someone else has accessed both Mr Meehan's house and his computer to carry out the downloads in question, " he said.

Mr Holderness added that two images were downloaded within 30 minutes of a file-sharing program being installed. He said it was likely that the owner was responsible for installing the software and downloading the images.

Mr Holderness told the court that the image found on Meehan's mobile phone, believed to be of a 15-year-old girl, had come from his computer.

During police interviews, Meehan denied using the computer to access any type of pornography, but later admitted viewing adult pornography.

Films with explicit titles suggesting they contained child pornography were previewed on Meehan's computer, but did not contain indecent images of children and did not form part of the charges.

However, Mr Holderness said the only way to find out if the material was child pornography was to preview it.

Giving evidence, Det Con Andrew James, of West Yorkshire Police, said the computer was protected by the password "reggie07" with "reggie" being Meehan's nickname.

The trial continues.