A business consultant was on Wednesday sentenced to four months in jail for having commercial sex with an underage escort, in a long-running online vice ring case.

Edward Whistler Goh Ngian Meng, 51, is understood to be the 26th man to be given punishment for the crime. He suffered a panic attack in the dock last month, after being convicted on two counts of paying $450 for sexual services from the 17-year-old.

His first offence took place at Hotel 81 Bencoolen on Sept 29, 2010, and the second, at his former condominium in Telok Kurau on Oct 24.

Fifty-one men were charged with the offence last year. Goh is understood to be the fourth to claim trial. Swiss banker Juerg Buergin, 42, ex-navy engineer Kwa Wee Nam, 34, and Indonesian Reyner Desvando Suhartono, 29, all of whom claimed trial have been sentenced.

Kwa was sentenced to four months on Oct 17, while Buergin, a former executive director with UBS, was understood to have left Singapore in August after completing a 19-week jail term for two charges. Suhartono was jailed for four months. All the 22 other men who have been sentenced pleaded guilty. The maximum penalty for the offence is a seven-year jail term and a fine.