Dottie Sandusky, the wife of former Penn State assistant football coach Jerry Sandusky, arrives at the Centre County Courthouse in Bellefonte, Pennsylvania.

Bellefonte - Jerry Sandusky's wife of 45 years testified on Tuesday that she had not seen any inappropriate behaviour between children and her husband, a former Penn State assistant football coach who stands accused of sexually abusing 10 boys over 15 years.

The jury also heard from a psychologist called by the defence who said Sandusky suffers from a personality disorder that is characterised by a deep need for attention and inappropriate, provocative behaviour.

Dottie Sandusky denied testimony by several victims that they had stayed overnight numerous times at their home in State College, Pennsylvania, saying that children would sleep overnight as guests perhaps only once or twice a month.

During his wife's testimony, Sandusky, who was dressed in a dark suit, sat as he has through most of the trial - hunched over the defence table, staring at the witness, sometimes resting his chin on his hand.

The former defensive co-ordinator for Penn State's successful football programme faces 51 counts of child molestation that carry a sentence of more than 500 years in prison.

The case has focused renewed national attention on the issue of child sexual abuse and prompted the firing in November of Penn State President Graham Spanier and legendary head football coach Joe Paterno. Paterno died of lung cancer in January.

Dottie Sandusky, who said she was known as “Sarge” for her firm hand in running a large home, also denied testimony by Victim 4 - as he is identified in court papers - of an alleged sexual encounter with Sandusky while on a trip to the 1999 Alamo Bowl in Texas. The accuser said Sandusky had tried to force him to perform oral sex on him in the hotel bathroom when his wife walked into the room, breaking up the encounter.

But Dottie Sandusky said she had entered the hotel room and her husband and Victim 4 were arguing because the boy had refused to attend a banquet even though Sandusky had paid $50 for a ticket.

“‘We did this for you, and you've got to do this for us’,” she recalled her husband saying.

Eight alleged victims, now men aged 18 to 28, testified for the prosecution last week, describing in often graphic detail being molested by Sandusky as boys, including oral and anal sex and shared showers. Two other alleged victims have never been identified. - Reuters