The controversy surrounding Olympian boxer Imane Khelif was amplified tonight after she emphatically beat a Thai woman and advanced to the finals.

There have been calls for the 5ft 10in Khelif, 25, who is now one win away from Olympic gold, to be banned from competing due to a suggestion she may not be biologically female.

She is not transgender — there are photos from her childhood as a little girl — and Olympic organizers say the Algerian passed all gender eligibility checks.

However, Khelif was disqualified from last year’s World Championships by Russian-led governing body IBA after failing a gender test shortly before she was due to fight for a gold medal.

Some health experts believe she has a differences in sex development (DSD) disorder, an umbrella term for individuals who have a group of conditions where their reproductive anatomy does not match the typical definition of male or female. 

Khelif denies this.

DailyMail.com spoke to two women born with DSDs — plus doctors — about whether they think Khelif has an unfair advantage over her female opponents.

Hannah Twigg is an intersex woman from the UK who has a condition called Complete Androgen Insensitivity Syndrome (CAIS).

It means that although she has the XY chromosomes of a male, her body does not respond to testosterone because of a genetic mutation.

As a result, she has developed the traits of a female — because testosterone has no effect on her sex development.

Ms Twigg said: 'I was involved a lot in sports teams in high school, playing on sports teams.

'[But] I never felt as though my condition gave me an advantage or disadvantage in sport.' 

She added: 'I would like to take the opportunity to say that Imane Khelif does not owe anyone an explanation for her gender and identity.' 

Because testosterone does not act on her body, this means she has not gone through the surge in muscle mass that males experience at puberty.

After puberty, men have about 40 to 50 percent more muscle mass than women.

Some experts suggest Khelif may have a different condition, however, called 5-Alpha-Reductase Deficiency (5-ARD).

In this, an individual is biologically male — with XY chromosomes — but their body does not respond to a crucial hormone in the womb, leading to the development of a vagina or indeterminate sex organs externally.

Internally, however, they have undescended testicles, which start to release testosterone when someone hits puberty — leading to the development of male characteristics including a surge in muscle mass.

Previously, the South African mid-distance runner Caster Semenya was diagnosed with the condition — which led her to be barred from track events because of elevated testosterone levels.

Estimates suggest about one to two out of every 100 people in the US are born intersex or with DSD.

Alyssa Ball, who is also intersex and raises awareness of the condition, told DailyMail.com: 'I feel pretty emotionally exhausted speaking about the subject matter at hand.

'As an intersex person, of course I think she should be allowed to compete.

'Whatever "advantages" she may have are comparable to say someone else born with a physical build that is most advantageous for whatever sport.'

Dr Tommy Lundberg, a lecturer in physiology at Sweden's Karolinska Instituet, disagreed, however, saying she likely had a biological advantage because she has likely gone through male puberty.

He said: 'If Khelif does have 5-ARD, then that's considered male development during puberty and therefore and advantage.

'Being male is not a talent and should not be rewarded more than being female.

'The inclusion of athletes with male performance advantages in women's sport if a violation of the very important principles of fair and safe competition for female athletes.'

In tonight's fight, Khelif beat her competitor Janjaem Suwannapheng after overpowering the plucky opponent and landing bigger shots — before cruising to victory with a unanimous verdict.

She was cheered on by a noisy Algerian crowd, who were shouting 'Imane' before their boxer had even entered the arena. 

After winning, she skipped victorious circles around the arena before leaving to more cheers — ahead of her fight for the gold on Friday.  

Fiona McAnena, who works with scientists who research sex differences and is a director at UK-based women's sports charity Sex Matters, also said she likely had an advantage.

She said: 'It is not the fault of these young people that they have a congenital [developmental] condition and are registered as female when their chromosomes are male. This may be a shocking, surprising and traumatic thing even, to find out about.

'But all of that aside, women's sport is set up for people who have a woman's advantage and not a male advantage.

'If competitors have a male advantage, and have been through male puberty, then they don't belong in women's sport.'

Khelif's condition is not public, leaving experts only able to speculate on whether or not she may have a condition and, if so, which one.

But a recent statement tweak from the International Olympic Committee (IOC) suggests that she may be intersex.

On August 3, they updated a statement where they said 'this is not a Differences of Sexual Development' case' to 'this is not a transgender case'.

For her part, Khelif has said that she is a woman and vowed to continue competing.

In a statement, she said: 'I address my message to all the people of the world to adhere to the Olympic principles, according to the Olympic Charter, and to avoid bullying all athletes, because this has a great impact.

'It is capable of destroying people, killing people's thinking and minds, and dividing people.'

She previously dismissed the decision to ban her from the IBA's competition as a 'conspiracy' to stop an Algerian winning. 

Khelif's native Algeria has strong anti-LGBT laws in place, and its society does not tolerate transgender individuals.

The IOC interprets someone's gender at face value based on what is written in their passports.

They are also running the women's boxing competition amid a separate dispute with the IBA, which was barred from involvement.

In other categories, however, such as swimming — the association reserves the right to test athletes when there are concerns they may have a biological advantage.

Experts suggest the same should be done in boxing, saying it can be determined whether someone has gone through male puberty using a blood test — which can pick up higher levels of testosterone.