Blake Fielder-Civil overdosed on heroin after reading old text messages from his ex-wife, the late Amy Winehouse, his mother has revealed.

Blake, 30, was released from jail two weeks ago after serving 12-months of a 32-month sentence for burglary and possession of an imitation firearm.

It was not long before he was found choking in his bed on Friday. Blake had battled with his own long-running fight against addiction. It was said he had overdosed after going out for a few drinks with a friend.

Blake's mother, Georgette, told the Irish Sun she feels Amy's old text messages may have had an effect on Blake after he was released from prison. He started using an old phone he did not have in prison and came across old touching texts from Amy. In one, the singer, who passed away in July 2011 aged 27, asked if she could be the godmother to Blake's son Jack, now 15 months.

Blake and Amy at the Coachella Music Festival in 2007.

Georgette said; “He had messages on his phone from Amy which he only got recently. He didn't have the phone in prison and he picked up messages from her when he was released. She said she wanted to be Jack's godmother. The grief for Amy started again, I fear he may have been trying to take his own life.”

Blake had earlier told his partner Sarah Aspin, 34, the mother of Jack, he was deeply missing Amy.

Georgette has been keeping a bedside vigil and praying for Blake in hospital. Medics plan to keep him on a life-support machine and in an induced coma for at least a week but said he should survive.

Amy's father Mitch has also said he is praying for Blake's recovery.