The murders took place between 2022 and last week.
“Unfortunately, and this is very sad, the suspect alleged that his first victim was his wife… who he strangled to death, before dismembering her body and disposing of it at the same site,” Mr Amin added.
Khalusha was reported to have taken police to his home, where they found 10 phones, a laptop, identity cards, female clothing and a machete officers believe was used to chop up victims.
The nine bodies recovered so far are all of women, aged 18 to 30.
Police are still questioning the suspect and he is expected to appear in court on Tuesday.
A second man was arrested after allegedly being caught with a phone belonging to one of the victims.
Police under scrutiny
The dumping site for the bodies was close to a police station, leading the country’s police watchdog to announce it would investigate whether officers were involved.
The Independent Police Oversight Authority said it was undertaking a preliminary investigation following “widespread allegations of police involvement in unlawful arrests [and] abductions”.
The police are under intense scrutiny after widespread anti-government protests late last month during which dozens of demonstrators were killed.
Officers are often accused of using excessive force and carrying out unlawful killings or running hit squads, but few have faced justice.