Mr Haigh has reportedly been charged with slander on the basis of comments made about Leeds United’s former owners GFH eight months earlier on his Twitter account.
Mr Haigh had been due to fly home to the UK in November after serving 18 months of a two-year sentence in the United Arab Emirates for financial misappropriation.
A day before his release he was detained again after his former employer, investment bank Gulf Finance House (GFH), complained about remarks allegedly made on Twitter.
His case has now been taken up by Human Rights Watch, which says authorities in the UAE should drop the slander charges, release Mr Haigh and scrap the law that criminalises slander.
The influential human rights organisation has criticised the Middle Eastern nation’s “repressive” cybercrime laws and said Mr Haigh has had hearings to consider his case postponed six times since being detained in November.
Joe Stork, Deputy Middle East Director for HRW, said: “If UAE businessmen can have their partners locked up when they don’t like the tone of their tweets, one has to question whether the UAE is a safe place to make any form of criticism.
“The UK government should make very public calls for David Haigh’s immediate release and scrapping of the criminal slander law.”
Mr Haigh’s UK-based lawyer, Alun Jones, has said that he has concerns about his client’s physical and mental well-being. On March 3, a judge adjourned his trial for a sixth time until March 21.
A spokesman for Mr Haigh said: “David’s continuing incarceration in Dubai, almost two years after being tricked into flying into there from the UK, is a scandal.
“As Human Rights Watch makes clear, he has now been held in jail without trial for 15 weeks accused of abusing GFH on Twitter at a time when he was in jail without access to social media.
“David believes that his continuing detention is another example in his case of Dubai being as a corporate jail to force the resolution of commercial disputes.
“The same tactic was used in 2014 to trick him out of the jurisdiction of the UK and have him incarcerated for 14 months without trial with all his assets frozen.
“This has meant that David has been comprehensively disabled in terms of being either at liberty or financially able to defend himself against what he considers are entirely unfounded allegations.
“David welcomes Human Rights Watch’s intervention in the case and its call for the UAE authorities immediately to drop the charges of slander, release him and scrap the law that criminalises slander.”
HRW says Article 20 of UAE Federal Law No. 5 of 2012 on Combating Cybercrime, which makes it a criminal offense to make slanderous comments online, is “at odds with international human rights law”.
Mr Haigh, who was a director at United for just over a year in 2013-14 after leading GFH Capital’s negotiations to acquire the club, was originally arrested in Dubai on May 18 2014.
He was initially detained without charge for 14 months and had his worldwide assets frozen before being convicted in August this year of misappropriating items of monetary value from a position of trust from his former Dubai-based employer.
He was sentenced to two years in prison – the majority of which he had already served – but is reportedly considering seeking a retrial of his criminal conviction.