Women were denied access by security personnel on Tuesday (February 16) morning, with the FIVB admitting there was a "slight misunderstanding", before claiming this had been resolved, with full access restored.

The world governing body have hailed the event as a major step forward and a "first" due to the complete absence of female spectators at indoor events in Iran since the ban was first introduced in 2012.

In a statement, they also speculated the incident on Tuesday was a "politically motivated stunt".

This has been strongly rejected by Minky Worden, director of global initiatives at Human Rights Watch, who insisted this claim "gravely endangered" the safety of women trying to attend.

Worden insisted that, while some of those trying to gain access were activists, they were all dressed conservatively and accompanied by their families, were carrying no banners and uttering no political slogans.

Worden claimed that no woman she had spoken to had been able to enter the stadium, although multiple pictures and videos have been circulated of female spectators in the arena.

It has been suggested that some of those women present may have been planted there deliberately by the Iranian authorities and were not general members of the public.

"If even one woman was excluded after the FIVB promise, then that is a violation of the Olympic Charter and the FIVB's own constitution," Worden told insidethegames.

"After years of women being excluded by state security, the FIVB should have been at the gates.

"They dropped the ball in a very serious way.

"We gave this a fair chance, but it was a dismal failure and dangerous for women."

A 27-year long rule banning women from attending football matches in the Islamic country was controversially extended to volleyball in 2012.

The ban gained worldwide publicity in 2014 following the arrest of British-Iranian woman Ghoncheh Ghavami.

Ghavami, arrested for "propaganda against the regime" after attending an FIVB World League match in capital Tehran, spent 151 days in Evin prison before she was released and charges eventually dropped. 

The FIVB were initially criticised for a lack of action but vowed to work with Iranian authorities and promised not to allocate any more events to the country until the ban was lifted.

Both the World Tour events and indoor World League matches scheduled for later this year were awarded in apparent violation of this decision.

FIVB general director Fabio Azevedo, the official responsible for negotiating with the Iranians, told insidethegames in October they were prioritising a carrot rather than a stick approach to apply pressure to the Iranians to change their approach, a method they still believe will prove successful before the Olympic Games in Rio de Janeiro in August. 

This approach has been criticised by Worden, who claims football body FIFA have not awarded events to Iran since the ban on women was introduced after the Islamic Revolution of 1979.

"I am sure the FIVB supports gender equality," she said

"But they cannot just support it when it is easy - it's when it is hard that it is most important.

"The situation in Iran is hard, because hardliners are threatening women, but the FIVB cannot sweep it under the carpet.

"Why is the FIVB using the carrot when Iran is using the stick?"

It is vital the issue is solved in the next few months, Worden claimed, because of the added profile and opportunities brought by an Olympic year, as well as the current climate of reform in Iran under President Hassan Rouhani.

Rouhani said there "must be equal opportunities for women" after replacing Mahmoud Ahmadinejad in 2013.

He is handicapped, however, by other more conservative groups, including Supreme Leader Ali Khamenei, the head of state whose power over many areas, particularly domestic affairs, is considered greater than that of the President.

Other bodies are being urged to better support the FIVB in pushing for the ban to be lifted, including the International Olympic Committee (IOC).

When asked about this today, IOC Presidential spokesperson Mark Adams referred insidethegames to the FIVB statement claiming that, "for the most part women have been allowed to attend the men's beach volleyball event - a first in recent years."

The week-long men-only competition ended with victory for Qatar's Brazilian-born Jefferson Santos and partner Cherif Younousse, who beat Russia's Oleg Stoyanovskiy and Artem Yarzutkin 21-13, 14-21, 15-12 in the final today.