An army officer suspected of murdering at least seven people in Cyprus reportedly confessed to the serial killings in writing, saying he wanted “to go to prison”.

As Scotland Yard detectives joined police in investigating crimes described as unprecedented in scale, local media said the Greek Cypriot suspect decided to confess to the deaths of five foreign women and two children when he realised the evidence against him was unassailable.

Police also say the suspect, who has been remanded in custody but not charged, has confessed.

The adult victims were domestic workers employed in households on the island.

“I am bored. I want to go to prison. Bring some paper so I can write it all,” the suspect, identified as 35-year-old Nikos Metaxas, was quoted as saying by the leading daily, Politis, before he made the 10-page confession.

The National Guard captain admitted using the pseudonym Orestis to meet the women on a dating app.

News of the confession came as specialist divers, deploying a robotic camera, continued to search two manmade lakes south-west of Nicosia, the capital, where Metaxas claims he dumped three of his victims.

Four bodies have been found so far in a case described as the Mediterranean island’s first known serial killings.

The remains of a woman were discovered in a suitcase in the toxic red waters of one lake on Sunday. The body was discovered in a foetal position and fully dressed, in an advanced stage of decomposition.

Following the failure of a postmortem to confirm identification and cause of death, police said they were awaiting the results of DNA and histopathological tests.

The victim is believed to be either Livia Bunea, a 36-year-old Romanian who was reported missing with her eight-year old daughter, Elena Natalia, in September 2016, or 30-year-old Maricar Arquila from the Philippines, who disappeared in December 2017.

The three other apparent victims were found naked, bound and wrapped in sheets. They include two Filipinas retrieved from an abandoned mineshaft and a woman thought to be Nepalese discovered at an army firing range after the suspect led investigators to the site.

On Wednesday, the police spokesman Andreas Angelides told the island’s news agency that statements were being taken and electronic data examined as efforts intensified to crack crimes that had gone undetected for at least three years.

The search for the bodies was being hampered by poor visibility in the lakes’ waters, the byproduct of years of mining in the area.

Greek Cypriot authorities have come under criticism for the perceived laxness with which they have handled the cases of foreign women reported missing on the island. Both the head of police and justice minister have faced calls for their resignation, with protesters holding a vigil outside the presidential palace last week.

Campaigners say the island nation has scores of unsolved missing persons cases, with many believed to be migrant women. The EU’s most eastern member state has a sizeable population of workers from the Philippines employed by the island’s middle class.

In an editorial, the Cyprus Mail accused the police force of racist disregard for women who had come to the island “to scrape a living”.

Those who took up the case of Bunea were brushed off by police officers saying they believed she had fled to the war-partitioned island’s Turkish-controlled north. A friend who reported the mother and child missing claimed she was not even called in for a statement when she confirmed the disappearances to a local police station.

“And there is no escaping the fact that had they done their jobs in the case of Bunea, five lives could have been spared,” the paper opined. “Perhaps the police’s utter disregard for the safety of poor foreign women, including single mothers, reflects the attitude of our society, which is not particularly concerned about protecting weak, impoverished and disempowered foreigners working in Cyprus.”

The killings came to light last month when heavy rains revealed the body of a 38-year-old Filipina, Mary Rose Tiburcio, hidden in an abandoned copper mine close to a lake.

A tourist, who spotted the body as he took photographs in the area, immediately contacted police. The woman and her six-year-old daughter had gone missing nearly a year earlier.

Six days later, the remains of a second Filipina, named as Arian Palanas Lozano, were also found at the site.