There was no way Peter Lim Sin Pang would have known that the Singapore Civil Defence Force (SCDF) would need to acquire radiation detectors when he had a tryst with Ms Pang Chor Mui in 2010.

In fact, no one in the SCDF could have predicted the need, since it was sparked by the Fukushima nuclear crisis in Japan, which was caused by an earthquake in March 2011, said defence lawyer Hamidul Haq in court on Friday.

Mr Haq is defending Lim, the former SCDF chief who is charged with corruptly obtaining oral sex from Ms Pang in exchange for furthering the business interests of her then employer.

He said that it was because of the crisis in Japan that resulted in the SCDF being asked by the Ministry of Home Affairs to scan passengers arriving from Japan for radiation. The SCDF then called for a tender for radiation monitors.

It is this April 2011 tender that the prosecution has linked to Lim's and Ms Pang's sexual encounter in May 2010, alleging that he had tipped her off about it before it was made public.

While cross examining prosecution witness Roger Wong Kok Buk from the SCDF, Mr Haq said Lim could not have possibly predicted in May 2010 that an earthquake would happen a year later.

The defence lawyer also made the point that Lim's decision to call for an open tender, as opposed to limiting the tender to SCDF's existing supplier Secom, had been in line with procurement principles. It was also done in the best interests of the SCDF, he added.