Prime Minister Dr Mahathir Mohamad took a stab at political rival Najib Abdul Razak when explaining Putrajaya's position in banning Israel's athletes from a world championship swimming meet to be held in Malaysia.

Lending his presence to the Pakatan Harapan by-election campaign efforts on behalf of candidate M Manogaran on the eve of polling day, Mahathir sought to appeal to Malay voters by explaining Putrajaya's stand on the matter.

He told the local residents that Malaysia had to make a stand despite garnering international criticism over its decision.

"(So) what is the reason we don't allow Israelites to come here? We say they are crooks (penyangak), and we just got rid of one crook," he said to residents of Felda Sungai Koyan today.

Mahathir had earlier this month announced that Malaysia would not grant visas to Israeli athletes for the World Para-Swimming Championships to be held in Kuching in July.