Church leaders and human rights campaigners Wednesday welcomed a ban by the Philippines on organ transplants to foreigners but cautioned that loopholes may still allow kidney trafficking to persist.

The health department Tuesday banned most organ transplants to foreigners and vowed tough punishments for lawbreakers to stem a thriving trade in poor Filipinos selling their own kidneys.

The highly influential Catholic Bishops Conference of the Philippines and the Philippine Society of Nephrology both called the order a good step in the fight against organ trafficking.

"That is a step in the right direction," said Albert Chua, an official of the grouping of the country's renal disease experts.

But he warned that the government must also address other related issues, including the requirements of thousands of Filipinos who urgently need kidney replacements to survive irreversible renal failure.

The Philippines is a world "hotspot" for human organ trafficking, according to the renal specialists' group.

The kidney doctors and the bishops have raised concerns over the rampant trafficking of kidneys from impoverished and poorly educated Filipino "donors" who part with one of their kidneys for about 3,000 dollars, usually bought by Arab or Western recipients who undergo the surgery in Philippine hospitals.

Bishop Jose Oliveros, head of the bishops' bioethics committee, said the "temporary ban among the foreigners having their kidney transplant here is a good step to stop the rampant sale and commercialisation of organ donation."