One fan says they have been "sobbing uncontrollably" after watching the latest episode of Game of Thrones, which leaked overnight.

The episode was accidentally leaked by HBO in Spain, four days before its official screening date, The Daily Mail reported.

On-demand subscribers to the pay-per-view channel had access to the latest instalment, titled Death Is The Enemy, for a full hour before the blunder was addressed and the episode removed - but not before it was ripped and shared online.

The episode has since been uploaded to torrent sharing sites, while various spoiler-laden scenes are available to watch on social media platforms Reddit, YouTube and Instagram.

Referencing the incident, a spokesperson told MailOnline the error - which affected HBO in Spain and Nordic territories - was caused by "a third party vendor".

"We have learned that the upcoming episode of Game of Thrones was accidentally posted for a brief time on the HBO Nordic and HBO Espaņa platforms.

"The error appears to have originated with a third party vendor and the episode was removed as soon as it was recognized. This is not connected to the recent cyber incident at HBO in the US."

Taking to Twitter, those who have streamed episode, which focuses on Jon Snow's dramatic confrontation with the Night King and his army of White Walkers, admitted it is one of the most thrilling instalments yet.

https://twitter.com/HGallimore21/sta...09637050535939

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https://twitter.com/WailaHusnain/sta...68174795202560

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The mistake comes after four people were arrested in India for leaking the fourth episode from the current season before it aired, police in Mumbai announced on Monday.

Already the most pirated show in TV history, the hit fantasy drama has been plagued by leaks in recent weeks following the premiere of the penultimate seventh season.

After receiving a complaint from the Mumbai-based company Prime Focus Technology, "we investigated the case and have arrested four individuals for unauthorized publication of the fourth episode from season seven," Deputy Commissioner of Police Akbar Pathan told AFP.

He said three of the suspects are current employees of Prime Focus, while the fourth is a former employee. All four are accused of criminal breach of trust and computer-related offences and would be detained until August 21 amid an investigation.

Prime Focus Technology is responsible for storing and processing episodes of Game of Thrones for the video-streaming app Hotstar, which is a subsidiary of the local broadcaster Star India, local media outlets said.

The four arrested possessed official credentials giving them access to the episodes of the popular series, the reports added.

The leaked episode, titled The Spoils of War, aired in both the US and India on August 7.

Its centerpiece was a heart-pounding battle sequence featuring a dragon, and it ended with a cliffhanger, which was resolved in its following episode, Eastwatch.

The India leak is believed to be unrelated to a group of hackers known as 'Mr Smith,' which on Sunday released new episodes of Larry David's Curb Your Enthusiasm, five scripts of Game of Thrones and five months worth of internal HBO emails.

A week prior, the hackers released episodes of two other HBO shows, the sports drama Ballers starring Dwayne Johnson and the comedy series Insecure.

The massive data dump was carried out after HBO reportedly refused to pay the hackers up to US$7.5 million in ransom money.

Game of Thrones has won more Emmy Awards than any scripted show in history and airs in 170 countries, with viewership figures shattering records across the world.

As well as being a hit globally, it has a massive fan base in South Asia.

Showrunners David Benioff and DB Weiss last year announced the shortened run of seven and six episodes for the final two seasons and confirmed the summer return for season seven, a departure from the usual April premieres.

MailOnline has contacted HBO representatives for further comment.