A man accused of plotting an acid attack on his three-year-old son has told a jury he was "never" involved and was "shocked" to be arrested.
The boy, who cannot be identified, suffered serious burns to his face and arm at the Home Bargains store in Worcester on July 21 last year.
His 40-year-old father denies conspiring to commit grievous bodily harm along with six other defendants.
But he claims his co-accused offered to find "private investigators".
Prosecutors allege that the father "enlisted others" to carry out the attack.
Giving evidence for the first time at Worcester Crown Court, the father - speaking through a Dari interpreter - said: "No, never" when he was asked if he arranged for acid to be thrown on his son.
He said he was "very shocked" to be detained over the attack which he said he only learned about when he was arrested at his Wolverhampton home.
However, in court he also said he had hired a private investigator, telling the jury he did not trust his wife to look after the children.
And he claimed that when he told his old workmate and co-accused Jabar Paktia about hiring investigators, Mr Paktia had made him an "offer".
The father said: "He told me that he knows somebody, to do the private investigation job at a cheaper rate - and better."
Asked who that "somebody" was, the male replied: "Saied Hussini."
He claimed that during a conversation lasting "an hour to an hour-and-a-half", Hussini offered the services of "a lady and a man" to carry out "private investigation" on his wife.
But, the father denied knowing anyone might have been following his son with acid and denied telling his wife she had "humiliated" him after the couple split and she left the family home with the children.
The father hoped to paint the mother as "unfit" and win more contact with the child, prosecutors previously told jurors.
Jurors were previously shown CCTV footage of the moment the boy was attacked in the store in the Tallow Hill area of the city, and heard how he screamed "I hurt" afterwards.
The boy's father also denied a claim by his wife that he had asked an imam about killing her and the children because she had left him.
The father, originally from Afghanistan, is on trial alongside Adam Cech, 27, of Farnham Road, Birmingham, Jan Dudi, 25, of Cranbrook Road, Birmingham, Norbert Pulko, 22, of Sutherland Road, London, Martina Badiova, 22, of Newcombe Road, Handsworth, Birmingham; Saied Hussini, 42, of Wrottesley Road, London, and Jabar Paktia, 42, of Newhampton Road, Wolverhampton.
The trial continues.
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