On Sunday night, Bollywood superstar Shah Rukh Khan beat up director Shirish Kunder, the husband of Khan's former best friend Farah Khan (no relation).

According to witnesses, Khan went after Kunder at a party hosted by Sanjay and Maanayata Dutt at a popular nightspot in Juhu, India, hosted to celebrate big returns on the new film Agneepath.

But as fans of the Bollywood heavyweights try to confirm what happened last night, more are interested in what supposedly set SRK off.

Rumor has it that Kunder not only caused the actor and Farah Khan to drift apart and mocked him for his movie roles, but actually followed SKR from room to room at the party until both the actor and his host had had enough.

'Only a spineless old man would attack from behind.'

Conflicting reports have been surfacing as to what started the fight between Shah Rukh Khan and Shirish Kunder on Sunday.

According to Kunder, Khan went after him with absolutely no provocation.

I didn't even know Shah Rukh was at the party! he told The Times of India. I was taken completely off-guard.

Kunder went on to assert that Shah Rukh Khan didn't even attack him head-on, which would have given him a chance to defend himself.

I challenge him to an open fight, Kunder said. Only a spineless old man would attack from behind.

Guests at the party, however, say Shirish Kunder was the one antagonizing Shah Rukh.

Kunder was in high spirits, and was badgering SRK from the time he arrived, following him around the venue, one witness told The Times.

The visibly inebriated director even followed Khan into the bathroom. That was when the actor lost his temper, with some guests saying he slapped Kunder and others claiming that he punched him as well.

Kunder Mocks Khan: 'I just heard a 150 Cr firework fizzle.'

With so many conflicting stories, it's difficult to say what set Shah Rukh Khan off at Dutt's party on Sunday night.

What is certain, however, is that things have been going sour between SRK, Farha Khan and her husband Shirish Kunder for some time now.

After years of being close friends, the two Khans had something of a falling-out last year, and many blamd Kunder for instigating the break. According to Northern Voices Online, the director has hated SRK ever since the actor refused to work on a new film, Joker, which Kunder was editing and directing.

More recently, however, Kunder took to Twitter when Khan's new film Ra.One came out to mock the movie's aniticipated box office earnings.

I just heard a 150 Cr firework fizzle, Kunder tweeted, a reference to the Rs 150 crore (roughly $31,393,888) the film reportedly cost to make.

Kunder has apparently continued to insult Shah Rukh Khan's film, to the point where Khan worked all night to avoid him at Riteish Deshmukh's birthday party in December 2011.

But SKR didn't hold back at Dutt's party, and sources say that the host, who has denied involvement, also landed a few punches on Kunder while he was trying to separate the two men.

'When Sanju heard about the fracas, he rushed in to break it up... [but] he too ended up landing a few blows on Kunder for allegedly sendin lew text messages to the host's wife Maanyata.

This same source told The Times that politician Bab Dewan also got involved, arguing with SRK and trying to get him to stop fighting.

According to guests at the party, Khan took off immediately after the fight ended, around 3:40 a.m., with Kunder leaving soon after.

'It saddens me.'

Battling over the how and why of the fight between Shah Rukh Khan and Shirish Kunder has carried over to Twitter, where the online fallout from the fight is simiarly divided,

I was present at Sanj's party, tweeted fashion photographer Dabboo Ratnani. & Without Any Bias I Fully Support Shah Rukh @iamsrk.

But Farah Khan, once SRK's best friend, took her husband's side. The director-choreographer, who was not at the party, claimed Khan and his boydguards jumped Kunder at the party with no provocation.  She blasted her former friend for disrespect and hypocrisy.

Shah Rukh has always told me that getting physical is the worst way to sort out a problem, and that it means the attacker has a personal or professional crisis going on, she told reporters.

It saddens me to see him doing the same now.

Shirish Kunder has already sent out a Twitter post saying he has no plans to file an official complaint against SKR. Shah Rukh Khan has yet to make a statement.