Greig Irving, 40, was giving evidence at the trial of his niece Kimberley Hainey, 37, who denies murdering her son Declan, concealing his body and pretending that he was still alive to prevent police investigating his death.
Mr Irving told the jury at the High Court in Glasgow that he helped Hainey, of Bruce Road, Paisley, to acquire heroin.
Advocate depute Andrew Stewart, QC, asked how she was paying for the heroin, and Mr Irving said: “With her benefits. She was also going up to her mother’s house or her aunt’s house and getting money from them.
“She was also getting what she said were doubles of Declan’s toys and clothing with labels still on them and taking them back to the shops and getting money or vouchers for them and then buying heroin.”
Mr Irving, who now lectures drug users in Renfrewshire about the dangers of addiction, told the court that he helped to return the goods to shops and then went with Hainey to get heroin.
Referring to her son’s belongings Mr Irving added: “She said it was Easter presents and Christmas presents that Declan didn’t need.”
He said that Hainey told him Declan was at Saltcoats with her mum and added: “She said she was missing him as she hadn’t seen him for a long time.”
Hainey denies all the charges against her.
The trial before Lord Woolman continues.