The extra-marital affair of a contractor was exposed after he told pressmen the heroic act of him catching a robber in Johor Baru.

The 44-year-old Singaporean informed Sin Chew Daily on Tuesday that he was injured while fighting a robber, who tried to rob his "wife".

After the news was published, a woman telephoned the daily claiming she was the wife of the contractor.

She said they have three children aged between seven and 21.

"Our relationship turned sour after he was having an affair with the woman," she claimed.

The daily's reporter attempted to contact the other woman but she hung up the phone upon hearing the question.