Social media users have been reacting with cynicism and disgust today following claims that police footage of Sandra Bland's arrest was edited before it was released.

Discrepancies in the clip were first pointed out by Ava DuVernay, the director of Oscar-nominated civil rights movement film Selma, who took to Twitter with her allegations on Tuesday night.

Since then, other people have been inundating the site with their comments.

One user asked Texas Police Department: 'What is Texas hiding? Makes one think Sandra Bland was indeed murdered while in custody.'

Another said: 'Someone should check the jail video they released too.'

Meanwhile Texas officials insisted on Wednesday that the 52-minute video had not been edited and that the glitches were due to technical issues. It said another version of the footage would be released.

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Accusations: Twitter users have been expressing outrage that police allegedly doctored footage of activist Sandra Bland being arrested on July 10. The police have denied the claims

The dashcam video showed a Department of Public Safety trooper trying to pull Sandra Bland from her car

'The video has not been edited,' said Tom Vinger, a spokesman for the Texas Department of Public Safety. He added that some of the video during a conversation between the trooper and his sergeant after the arrest of Bland was 'affected in the upload and is being addressed', and that DPS was working to repost it.

The department has also asked the FBI to investigate 'to ensure the integrity of the video'.

Director Ava DuVernay claimed that the video of the arrest of African American Bland, released by the department yesterday, shows clear signs of being altered.

The dashcam video, shot from the police patrol car, shows state trooper Brian Encinia pulling over 28-year-old Bland for failing to signal a turn, followed by a confrontation between the activist and the officer.

Police say Ms Bland, from Chicago, was found hanged in a Waller County jail cell three days after being arrested and charged with assault on a public servant.

But her family said she wouldn't have killed herself. Waller County District Attorney Elton Mathis said on Monday he would investigate the death as a homicide.

Controversial: DPS trooper Brian Encinia got Bland to leave the car by threatening her and told her she was under arrest

Outrage: Eva DuVernay, director of Oscar-nominated film Selma, has spoken out claiming that the police footage has been doctored

On Tuesday at 10pm, Ms Duvernay posted on Twitter: ‘I edit footage for a living. But anyone can see that this official video has been cut.'

She added: 'Glitches. Motion sensors. Clouds. Reasons from those who say SandraBland vid is pristine. Doesn't explain loops + audio cuts. But, um, ok.'

In a third tweet, she said in response to other users: 'I disagree. But not worth arguing about. Because the real issue is: What really happened to SandraBland? Missing info from start to finish. Why?'

Multiple allegations have been made about the 52-minute video - which can be viewed in full on YouTube - including claims that footage has been removed and looped to match the audio recording.

One of the most conspicuous moments in the footage comes at 25.12, when a man gets out of his truck in the centre of the screen and walks off screen to the right.

Ava DuVernay, the director of Oscar-nominated civil rights movement film Selma, tweeted these accusations

At 25:20, the same man reappears getting out of his car again, and the footage flickers before settling.

At 33:02, a a white car drives into the left-hand-side of the frame before disappearing and reappearing seconds later.

The same white car can be seen again driving into the frame at 33:50. The car drives into the shot, followed by a dark grey car.

Both cars disappear from the centre of the screen at 33.56, before reappearing again from the left of the screen.

The white car disappears again at 33.59, and both vanish again at 34:06.

Meanwhile the audio recording of the officer making a phone call to report the incident continues smoothly.

Sandra Bland, 28 (seen in a Facebook picture), was found dead in her Texas jail cell three days after being pulled over for an alleged traffic violation

In the police video she is ordered to put down her phone (left) before Encinia put her in handcuffs (right)

The video, recorded on July 10, shows the officer pulling Bland over, before a confrontation develops and she is arrested.

The confrontation between the two parties began when Encinia asked Bland to put out a cigarette and she responded 'Why do I have to put out a cigarette in my own car?'

He ordered her out of the vehicle and when she refused, he informed her she was under arrest.

Encinia also said 'I will yank you out of the car' and 'I'm going to drag you out.'

When Bland still refused to move, Encinia yanked her door open and appeared to try to drag her out physically before he eventually grabbed his Taser and yelled: 'I will light you up.'

Bland then exited the car and continued to complain about her treatment by the officer.

After being ordered to put down her phone, Bland said she would look forward to seeing him in court and a physical confrontation began off-camera after Encinia put her in handcuffs.

At various points during the confrontation, Bland said 'you are such a p***y', 'this make you feel real good, you're a real man', 'y'all strong', and 'South Carolina got y'all b***h a***s scared'.

In the course of the video, Bland claims the officer 'slammed her head on the ground'.

The officer claims that Bland kicked him, which is confirmed by his female partner.

As Bland and the police officer are off-screen throughout the confrontation, however, there is no footage of either assault taking place.

Bland family lawyer Cannon Lambert confirmed there is no footage of Bland kicking Encinia, as the Texas DPS had previously claimed.

Twitter users who watched the video have been condemning the police officer's actions during the arrest

The police officer's treatment of Bland has also been criticized by social media users, with one saying: 'After watching the video... what was Sandra Bland arrested for again? That part wasn't very clear.'

Her death at the Waller County jail in Hempstead, about 60 miles northwest of Houston, was ruled a suicide by the Harris County Medical Examiner's Office.

But her family expressed doubt that she would have killed herself - she had just moved to Texas for a promising new job at the university - and Waller County District Attorney Elton Mathis said on Monday he would investigate the incident as a homicide.

He promised that prosecutors would handle the case as thoroughly ‘as it would be in a murder investigation’, adding that it was ‘too early’ to determine what happened.

'Sandra Bland was very combative,' Mathis said. 'It was not a model traffic stop... and it was not a model person that was stopped on a traffic stop.

'I think the public can make its own determinations as to the behaviors that are seen in the video.'

The FBI and the Texas Rangers are also investigating.

Bland's family and others have called for a Justice Department probe and an independent autopsy.

Bland, seen in a police mugshot, would not have killed herself, say her family and friends

A three-hour video taken from outside a jail cell where Bland's body was found showed there was no activity in the hallway outside her cell for 90 minutes beforehand

In the video footage several staff members at the Waller County Jail are seen rushing to her cell on July 13

An EMS team also came to the scene and CPR was administered, but it was not successful

During a service on Tuesday at All Faiths Chapel on the Prairie View A&M University campus, more than a hundred people paid their respects to Bland, according to the Houston Chronicle.

Her mother Geneva Reed-Veal spoke at the end of the service honoring her daughter.

Reed-Veal said Bland told her that her purpose in life was to 'stop all social injustice in the South'.

The grieving mother said: 'I'm angry, too.

'All I want to know is what happened.

'There is not anywhere that I can see that my baby took her own life.

'Once I put this baby in the ground. I'm ready... this means war.'

Sandra Bland's mom Geneva Read-Veal (right) and sister Sharon during a prayer at the tribute service

Bland's mother (center) was hugged by family members at a memorial service for her daughter

Jeanette Williams places a bouquet of roses at a memorial for Bland near Prairie View A&M University

A three-hour video taken from outside the jail cell where Bland was found dead was released by Texas authorities on Monday.

The video shows no activity in the hallway leading to Bland's cell for about 90 minutes until an officer goes to check on her.

It shows a deputy reacting to what she sees while looking in the cell, triggering a frenzy of activity involving other deputies.

An EMT crew arrives with a wheeled stretcher.

The video does not show the inside of her cell or even her cell door.

Deputies and medical personnel are seen coming and going, but a body isn't visible.

Captain Brian Cantrell, head of the sheriff's department criminal investigation division, said the video was motion sensitive, indicating if nothing is taking place after a certain amount of time, it turns off.

He said the FBI has been given hard drives to determine if there's been any manipulation.

Cantrell said a guard checked with Bland about two hours before she was found dead and Bland told her, 'I'm fine'.

A video recorded by a bystander of Bland's arrest shows an officer holding her to the ground

Protesters rallied outside the Waller County Courthouse after marching from the jail where Bland died

About an hour later, she asked to make a telephone call from her cell and was advised the phone was on a wall in the cell, according to Cantrell.

There is no record of her ever making a phone call, he said.

Mathis also said jail records show Bland was offered a medical checkup but declined.

Cantrell declined to describe Bland's death in detail.

He described the plastic garbage bag used as a ligature by extending his hands about five-to-six feet apart.

The bags, he said, had been approved by a jail inspector, but have since been removed from all cells.

Relatives and friends have insisted she was upbeat and looking forward to a new job at Prairie View A&M University, the school where she graduated in 2009.