An environmental group called for a halt to baptisms in the Jordan River where tradition holds that Jesus was baptised, saying the waters there were dangerously polluted.

"Friends of the Earth Middle East call on regional authorities to halt baptism in the lower Jordan River until water quality standards for tourism activities there are met," said a statement from the group.

The group issued the call following media reports that Israel's health ministry had urged the tourism ministry to stop people bathing in the river, saying it posed a health risk.

In recent years the flow of the river has slowed to a dirty trickle as fresh water running into the river has been replaced with sewage.

"Sadly, the lower Jordan River has long suffered from severe mismanagement with the diversion of 98 per cent of its fresh water by Israel, Syria and Jordan and the discharge of untreated sewage, agricultural run-off, saline water and fish pond effluent in its place," the statement said.