Friends and family of Shane Todd met with police at his apartment after his death

Friends and family of American researcher Shane Todd had met with police officers in his Chinatown apartment five days after his body was discovered there last June, a colleague of Dr Todd told the court on Thursday.

But Dr Jeffrey Soon, who worked with Dr Todd at the Singapore Institute of Microelectronics (IME), said he did not hear the police officers speaking much.

"They (the police) were listening most of the time," said Dr Soon, adding that it was mainly Dr Todd's mother, Mary, discussing how her son might have died.

He added that there was talk of an "automatic screwdriver" which Dr Todd might have used to attach the strap to his toilet door, but Dr Soon told the court that he did not see such a tool in the apartment.

There was, however, no mention of nuts, bolts and pulleys during the three hour discussion between the police and Dr Todd's parents, his brothers and friends.

The court also heard that the American researcher began working longer hours and even the weekends after he transferred to a new team in July 2011, to a point where he no longer met Dr Soon and other friends at IME for lunch or dinner.

"He looked more tired and exhausted most of the time," said Dr Soon, who said his friend also started using the weekends to prepare slides for work.

But Dr Todd never told him he was depressed, or that he thought his life was in danger, added Dr Soon.