Amy Winehouse's marriage is in tatters after she ignored her jailed husband's birthday this week.

The singer, 24, failed to send a card to or visit Blake Civil Fielder in Pentonville Prison when he turned 26 on April 16 and according to friends she is now living as a "single woman".

Blake, who is charged with assault and conspiracy to pervert the course of justice, allegedly threatened Amy with divorce for repeatedly missing prison visits last year.

Scroll down for more...

Absent: Amy was out with Mark Ronson when she should have been visiting her husband in early January

To make things worse, when she was scheduled to see her husband in January the troubled star was pictured out on the town with producer Mark Ronson.

A month ahead of their first wedding anniversary, he is now reportedly self-harming on a regular basis due to her continuing absence while he is behind bars.

A friend of the singer's told The Sun: "Amy does everything she can not to visit. She forgets she is married half the time. There are a few men she is close to and Blake can't stand it."

His wife's growing nonchalance towards their marriage could be why he has converted to Roman Catholicism in a private ceremony in the prison chapel.

"Blake has been taking the religion more and more seriously," a source at Pentonville prison told us.

"Blake has been seeing the prison's chaplain most days since he has been inside."

Scroll down for more...

In happier times: Blake and Amy were inseperable but her failure to visit him in Pentonville has reportedly left their marriage in tatters

The source continued: "The whole prison experience has been extremely stressful for Blake.

"He stands out like a sore thumb with all the other prisoners because of who his wife is.

"Since he has been here he has been making a huge effort to kick his drug habit and get his life back on track.

"He was never interested in religion before, but the chaplain has been a friendly face he can turn to."

Blake never struck us as the Bible-bashing type, although he does dress a bit like a preacher.

We can also reveal that he has been writing for the prison magazine.

Our source said: "Blake has written for the magazine a few times, but this is regarded as a privilege and can be lost if any of the rules are broken, such as failing a drugs test."

Scroll down for more...

Troubled: Blake, pictured before being taken into custody, has turned to religion

The news that Blake has decided to become a Catholic will probably be yet another blow for Amy's Jewish family, who have made no secret of their suspicions of him.

Meanwhile it has been reported that Amy will not release her third album until next year, after she cancelled recording sessions in the Bahamas.