RIYADH, April 2, 2008 (AFP) - Saudi Arabia's religious police have been implicated in the deaths of two men and two women after a car chase near the Muslim holy city of Medina, the Arab News daily reported on Wednesday.

Witnesses told the English-language paper that members of the Commission for the Promotion of Virtue and Prevention of Vice pursued the car before it overturned 20 kilometres (12 miles) outside the city on Tuesday.

'Commission officials were chasing the car in which the four were travelling,' one unidentified witness said.

Three passengers died at the scene and the fourth died later in hospital.

The commission's chief in Medina, Fahd al-Khidr, called the allegations baseless and denied that his men were involved.

The powerful religious police enforces a strict Islamic moral code in ultra-conservative conservative Saudi Arabia, where women are banned from mixing with men who are not relatives.

Local newspapers reported last month that two members of the religious police, commonly known as the Muttawa, were being held after the deaths of a young man and a female companion after another apparent car chase.

They died on March 16 when their car hit a truck and burst into flames after a four-wheel-drive vehicle chased them in the northwestern city of Tabuk.

The brother of the dead man told the Arabic-language daily Al-Watan that the religious police had been pursuing their car 'until the last moment.'

The religious police defended its officers, saying 'the search for the truth does not square with the contention that the patrol provoked the accident.'

The daily Okaz said one of the two religious policemen had also been implicated in the death of a man held in Tabuk last May for allegedly associating with a woman who was not a relative.

Three members of the religious police and a regular police officer were eventually cleared of causing his death.

Over the past year the 5,000-strong Muttawa has been investigated over a number of deaths during raids on homes and of people in custody.