A never-before-seen love letter from Amy Winehouse to her husband as he sat in prison contemplating their divorce has sold almost £5,000 at auction.The Rehab singer sent a Valentine's card to Blake Fielder-Civil - the production assistant who introduced her to heroin - in February 2009.Fielder-Civil, 26 at the time, was jailed for a 2006 attack on former pub landlord James King at Macbeths pub in Hoxton, East London.The card was sent amidst a chaotic time for the pair a year into their marriage., penned while Winehouse was on holiday in Saint Lucia in the Caribbean, where she had a fling with actor Josh Bowman. Auctioneers at Ewbank's in Guildford had expected the love note - presented in a frame beneath a large photograph of the star - to fetch between £2,000 and £4,000, but it eventually sold for £4,940 including fees. Fielder-Civil was jailed for the pub attack in July 2008 and released from prison in November on the condition that he go to rehab - a bill reportedly covered by his wife at the time, to the tune of £30,000.However, he was returned to jail a month later after breaching his bail conditions. Around the same time, Winehouse left for Saint Lucia.Photographs of her cuddling up to Bowman prompted Fielder-Civil to begin divorce proceedings from behind bars. A Valentine's Day card sent by Amy Winehouse to her husband Blake Fielder-Civil has sold for almost £5,000 at auction (pictured in a large frame with a photo of the singer) The card was addressed to Fielder-Civil at HMP Edmund's Hill in 2009 while he was locked up for an assault on a former pub landlord Amy Winehouse with her husband Blake Fielder-Civil in September 2007, shortly after their wedding in MiamiAddressed to 'Mr B, Civil WA7614' - his prisoner number - the card was sent to HMP Edmund's Hill, now Highpoint North, in Suffolk.It read: 'My husband, my Blake. Virtue is violent, and violets are blue. Blue - bruised is my heart since its beatings' for you.'I love you handsome, your Valentine 4 years strong. Your Amy'.She finishes the card with a kiss, which is also adorned with love hearts, and sent it with three stamps worth 2.25 East Caribbean dollars, equivalent to 61p today.Over the course of a twisting and turbulent relationship that lasted six years, Fielder-Civil served as WInehouse's muse after meeting her in a pub in Camden in 2005. He was the driving force for some of her best known songs and the seminal album Back to Black. After a brief break, the pair married in Miami in 2007 - shortly after her husband-to-be had introduced her to heroin, a decision he has since said he regrets.In a 2013 interview on The Jeremy Kyle Show, Fielder-Civil said of the drug: 'I don't think she would have ever experienced it without me.'She remained in the Caribbean for months - Bowman left in January, and denied reports of a romance - and performed at a local jazz festival before returning to Britain in the summer.Fielder-Civil was released from prison in February 2009, a month after he began divorce proceedings. The quickie separation - uncontested by Winehouse - was granted that July and finalised in August. Fielder-Civil received a £250,000 lump sum as part of the settlement - and would later try to claim another £1million from her estate.Winehouse died in July 2011 at the age of 27 from alcohol poisoning. Her relationship with Fielder-Civil was immortalised in the 2024 biographical film Back To Black, in which the couple were played by Marisa Abela and Jack O'Connell.The movie, which was made in cooperation with the Winehouse estate, received mixed reviews from critics for allegedly whitewashing parts of her story, including her introduction to drugs by Fielder-Civil.Daily Mail critic Peter Hoskin gave it one star in his review, noting: 'Back To Black shies away from the ugly stuff so thoroughly that it sometimes looks like a perfume ad: soft-focused and pretty.'Last month, Winehouse's father Mitch was ordered by a court to pay almost £1million to two of her friends after he accused them of auctioning some of her belongings without his permission.