HONG KONG - Director of the Marine Department of the Hong Kong Special Administrative Region (HKSAR) government Francis Liu said Saturday that he expected a probe into the Lamma ferry disaster to be completed in six months.

Liu said officers are looking into various aspects of the tragedy, including whether safety measures on board the two vessels were adequate and why did the Lamma IV sink within minutes after the collision.

Lai Tung-kwok, Secretary for Security of the HKSAR government, said the police have boarded and will continue to board the two boats to collect all necessary evidence.

"They are now conducting interviews on the survivors and witnesses to ascertain what they know so that we can piece up all available information to map out what happened in that night."

Lai said the police have already set up a hotline and have requested those witnesses to come forward to provide information.

The police have also set up a desk at the Lamma Island pier because they believe that during the incident, quite a number of Lamma residents were on board one of the vessels. Through setting up the desk, the police hope that they can obtain more information from eye witnesses on board the ship.

Two vessels -- "Sea Smooth" and Hong Kong Electric's "Lamma IV"- - collided off Yung Shu Wan Pier of Lamma Island at around 8:20 p.m. local time on Monday, when the city's residents were celebrating the National Day of China. A girl was certified dead in hospital last night, bringing the death toll of the disaster to 39.

Patrick Nip, Director of the Social Welfare Department of the HKSAR government, said more than a hundred social workers are helping families involved in the disaster.