A Cypriot army officer who has allegedly confessed to killing seven foreign women and girls over nearly three years appeared in court Sunday, while police said they had recovered a fifth body.

Captain Nicos Metaxas, 35, has not yet been formally charged over the murders -- dubbed the Mediterranean island's first serial killings, which have unleashed anger against what the president described as police "negligence".

Police told reporters on Sunday that they had retrieved a suitcase containing the remains of a human body at an acidic manmade lake southwest of Nicosia -- the second such find in eight days.

The body found on Sunday at the lake near the village of Mitsero is in an "advanced state of decomposition", police spokesman Andreas Angelides said.

He said a post-mortem would be carried out but did not say whether the body was that of an adult or a child.

Cypriot newspaper Phileleftheros reported that the body found on Sunday was that of a child.

Metaxas has allegedly confessed to the murder of five women, alongside daughters of two of the women -- a six-year-old Filipina and a Romanian girl.

The killings came to light in mid-April when unusually heavy rains brought the body of 38-year-old Filipina Mary Rose Tiburcio to the surface of the disused mine shaft where it had been hidden.

That triggered a murder investigation which led to Metaxas being arrested on April 18.

Days later, authorities found the body of a second woman in the shaft, believed to be Arian Palanas Lozano, 28, also from the Philippines.

These are the only two women to be officially identified.

The suspect then guided investigators to a well near an army firing range outside the capital, where police found the body of a third victim -- a woman thought to be from Nepal.

Police last Sunday recovered the remains of a fourth victim, stuffed in a suitcase at the bottom of the lake at Mitsero.

Rape allegation 

Metaxas was accused by police of raping a teenager during his court appearance on Sunday.

Neophytos Shailos, head of Nicosia's Criminal Investigation Department, told the Nicosia district court a Flipina woman, 19, came forward to file a complaint that Metaxas raped her.

The police chief told the court that the suspect denied the allegation when questioned about it.

People gather to light candles for victims of what is being dubbed Cyprus' 'first serial killer'. Photo: AFP

At the hearing on Sunday Metaxas was remanded in custody for a further eight days.

Shailos testified that the young woman said she made contact with the army officer online in 2016 when she replied to a modelling job for a photo shoot.

Metaxas appeared in court without a lawyer and told the judge he had "no objections" to being remanded.

Police say they have received a "deluge of information" about the suspect's activities with 350 witness statements taken and another 150 to be processed.

Cypriot authorities have been accused of failing to properly investigate the women's disappearances due to neglect and racism.

President Nicos Anastasiades on Friday fired top police officer Zacharias Chrysostomou a day after Justice Minister Ionas Nicolaou announced his resignation over the case.

Authorities have acknowledged that all the women and girls that the army officer has admitted to killing were reported missing to police, except the one from Nepal who was reported to immigration for being absent from her place of employment.

The police said Sunday they would continue to look for a third suitcase the suspect allegedly confessed to dumping in the lake.

Authorities said they were able to locate the second suitcase by using sophisticated equipment including a robotic camera flown in from the United States.

"We will persist in our efforts, conducting different kinds of tests in the area and elsewhere at a later stage," said Angelides.

He said police were still assessing data found on electronic equipment belonging to the suspect.