The Philippines is considering deporting all four suspects believed to be behind a string of robberies across Japan at the same time, the Southeast Asian country's justice minister said Tuesday, expressing hope to "solve the problem" by Monday.

Justice Secretary Jesus Crispin Remulla spoke to Kyodo News after announcing at a press conference earlier that one of the suspects, now being held at an immigration facility in Manila, is expected to be returned to Japan in the next few days.

Remulla had also said another suspect could be transferred to Japan in the latter half of this week, while the remaining two will be sent once certain conditions are fulfilled.

But the minister said later that he would comply with any request from Japan to deport all four suspects at once if Japan elects to make just such a request.

Photo taken on Jan. 30, 2023, shows a Bureau of Immigration warden's facility in Manila. (Kyodo)

The actual date of deportation remains fluid as pending local criminal cases could present obstacles to their swift deportation. Japan does not have an extradition treaty with the Philippines.

The minister also said late Tuesday afternoon that everything related to the suspects' deportation is "held in abeyance."

Remulla has said Manila aims to resolve the issue as soon as possible and in time for President Ferdinand Marcos Jr.'s visit to Japan, expected to begin in early February.

At Tuesday's press conference, the minister did not disclose the name of the first suspect expected to be transferred but said a criminal case against him had been dismissed.

He has previously told Kyodo that a pending case against Kiyoto Imamura, 38, was dropped at a local court on Jan. 25.

Remulla said the second suspect to be transferred has been accused of violence against a woman but that such a claim against him contradicts how the woman has interacted with the suspect. He said the woman regularly visits him at the facility and has displayed signs of intimacy.

Among the four suspects, Yuki Watanabe, who is believed to be a key figure in the group and may go by the name "Luffy," has been charged with violating the Philippine law on violence against women and children.

An investigative source has said Watanabe might be hoping the case will enable him to "avoid" being sent back to Japan.

The four men are believed to have remotely coordinated a series of robberies in Japan that began last year using an encrypted messaging app.

Remulla told the press conference that communications devices, including phones, have been confiscated from the suspects and that one of them owned six mobile phones.

Local investigators will work with police officers dispatched from Japan to search for evidence in the communication logs.

The four men likely include a person or persons thought to have masterminded the robberies under the names "Luffy" and "Kim."

Tokyo has sought the transfer of the four after Japanese police obtained arrest warrants on suspicion of theft in connection with a scam targeting elderly people in Japan.

Among the four detained at the facility, 38-year-old Watanabe was allegedly one of the leaders of the fraud group, which stole some 3.5 billion yen ($27 million) in around 2,300 cases between November 2018 and June 2020, police said.

Upon their return to Japan, police will arrest the four over the alleged scams and also investigate their suspected involvement in a string of robberies that have taken place across Japan since last year, including a Jan. 19 case in the suburban city of Komae in Tokyo that led to the death of 90-year-old Kinuyo Oshio.

Sources connected to the investigation into the robberies also said Tuesday that several incidents appear to have involved robbers posing as delivery people to gain entry to the properties.

Investigators in the December robbery in the capital's Nakano Ward and the Komae case have found transit forms with the victims' addresses on them, while in a robbery in suburban Tokyo city Inagi in October, a man wearing what appeared to be a delivery person's outfit was seen at the property.

Related coverage:

Manila hopes to deport Japan robbery suspects by 2nd week of Feb.

"Luffy" Japan robberies head suspected to be behind Manila fraud ring

Philippines willing to deport alleged robbery ringleader to Japan