From the very beginning, the quest of a pair of Iranian conjoined twins to become separate individuals was certain to grip the imagination of the world.

Ladan and Laleh Bijani were smart, articulate and determined. They were also 29, joined at the head and had been told repeatedly by medical experts that the probability of them surviving a separation surgery was zero.

That was, until they came across Singapore neurosurgeon Dr Keith Goh.

The Bijanis first read about Goh in 2001 after he successfully separated 11-month-old Nepali twins, Ganga and Jamuna Shrestha, who were joined at the head. He had used a new image guidance technology to plan the complex surgery previously unavailable to surgeons who had examined and turned down the Bijanis.

Encouraged, Ladan and Laleh wrote to Goh. By July 2003, they were ready to undergo their own separation surgery at the Raffles Hospital in Singapore.

The marathon operation begun on July 6 and within three days, the two women were separated. Tragically, they were also dead.

The fact that the odds were stacked so heavily against them was already sufficient cause for the surgery to attract widespread attention. But what split popular opinion afterwards was whether doctors were right to proceed with the risky procedure even with the twins' express consent.

The issues remain very much alive, as was evident during a spirited debate entitled 'The operation on the Bijani twins was proper from a medico-legal and ethical standpoint', at the Malaysian Law Conference last week.