The father of a boy accused of murdering Ana Kriegel has told his trial he looked "surprised" when Gardaí first called to their home.

Both his son and another 14-year-old boy deny murdering the Kildare schoolgirl at a derelict farmhouse in Dublin on May 14th last year.

The prosecution believes Boy B lured Ana Kriegel from her house in Leixlip, Co Kildare knowing what was to happen to her.

His co-accused, Boy A, is accused of violently sexually assaulting and murdering the 14-year-old schoolgirl.

During his evidence today, Boy B's father said his son looked "surprised" when Gardaí called to their home the night she went missing.

He said he stood behind his mother while she spoke to them.

During a walkthrough of the park where Boy B initially said he had last seen Ana, his father said he felt he was not fully open - that he was afraid of saying something.

The jury has already heard that he claimed he saw Boy A attacking Ana in an abandoned house near the park.

When he asked him why he told lies, Boy B's father said he told him he was afraid of Boy A.

Under cross-examination, he described his son as "very naive and immature" and he said he thought he would be punished by Boy A - that he would find him and beat him up.

Reporting by Frank Greaney