One of two people jailed for lying over the disappearance of three-year-old Ethan Williams is attempting to win his freedom.
Andrew Butt, 56, has applied to a judge to "purge his contempt" - meaning he is prepared to come clean over his role in the disappearance of Rebecca Minnock and her son.
The lorry driver was jailed last week alongside his partner, Louise Minnock, 52 - Ethan's maternal grandmother - after being found in contempt of court by Judge Stephen Wildblood QC.
Butt received a 28-day prison sentence for lying to police and withholding "crucial" information which would find Ethan after he disappeared with his mother during a bitter custody battle with her ex-partner.
He admitted he had driven the pair to Cheltenham in Gloucestershire from their home in Highbridge, Somerset, on the morning of May 27 but refused to say where he had dropped them off.
After 17 days on the run, Miss Minnock contacted the authorities in Oxford and handed herself in. Ethan was later handed over to his father, Roger Williams, 39, who had won custody.
The pair vanished on the day she was due to hand her only child over to his father following a court order.
Butt's application to "purge his contempt" will be heard in public before Judge Wildblood later today at Bristol Crown Court.
When jailing Butt, the judge explained that if he later told the truth, he could be released from prison earlier.
"You may ask to return to court before me, if you so elect, to purge your contempt," the judge said.
"That means that you may ask to come to the court and admit your guilt and explain the full truth about the morning of May 27.
"In that way, subject to the terms in which you do purge that contempt, it may be possible for me to release you earlier from your sentence.
"If you continue to conceal the truth about the May 27 it will be open to others, as I have said, to bring you back before me to sentence you further for your continuing contempt."
Earlier this week, the judge branded Miss Minnock "utterly irresponsible", saying that if everyone behaved like her there would be "anarchy".
Mr Williams, from Burnham on Sea, Somerset, described the last few weeks and months as a "time of immense anxiety and distress" and said he was grateful to everyone who helped bring his son home.
Ethan, who was born on January 25 2012, has lived with Miss Minnock since his parents separated in February 2013.
A custody battle began the following month. Miss Minnock made allegations about Mr Williams which a district judge later ruled were false.
On May 27, it was found that Miss Minnock had exposed Ethan to emotional harm and should only have supervised contact with him. It was ordered that the boy should live with Mr Williams full-time.