KUALA LUMPUR, Malaysia — Pastor Raymond Koh was driving along a tree-lined suburban street near Malaysia’s capital 15 months ago when masked men in black SUVs forced his sedan to a halt. Within 45 seconds, they had commandeered his car and taken him away. He has not been seen since.
Family members believe that government operatives were behind the military-style abduction and that, since then, the police have helped cover it up. Mr. Koh, they say, was most likely targeted in the belief that he preached Christianity to Muslims.
Now, with the ouster of Malaysia’s governing party this month after six decades in power, Mr. Koh’s family and supporters are calling for a new investigation into his kidnapping.
It is one of many cases that the new government is being called on to re-examine, including similar abductions, the deaths of prisoners in custody and politically charged murders.
“We should change the culture of impunity,” said Eric Paulsen, executive director of Lawyers for Liberty, a Malaysian human rights group.
The country’s new prime minister, Mahathir Mohamad, has said his government will restore the rule of law and ensure that the ousted prime minister, Najib Razak, is held accountable for billions of dollars that went missing from a state investment fund he oversaw.
In recent days, the police have raided residences associated with Mr. Najib and confiscated more than 350 boxes and pieces of luggage containing cash, jewelry, expensive watches and luxury handbags. On Friday, the police said the seized cash amounted to $28.6 million, and that the various luxury goods had yet to be appraised.
Mr. Najib has denied any wrongdoing. He told members of his party Sunday, “I’m not a person who steals what belongs to the people.” But he was called in for questioning on Tuesday by Malaysia’s reinvigorated anticorruption commission.
Human rights advocates are optimistic that the search for justice will not stop there.
Another figure likely to come under scrutiny is the former inspector general of police, Khalid Abu Bakar, who helped block inquires into the missing government funds and oversaw the investigation of Mr. Koh’s kidnapping, among other abduction cases.
Mr. Khalid, who retired from the police force last year, has pledged to cooperate with any inquiry.
Mr. Koh was abducted on Feb. 13 of last year as he was driving in broad daylight in the Kelana Jaya neighborhood near Kuala Lumpur, the capital.
His case has received considerable attention because his children, who conducted their own investigation, recovered video of the kidnapping that had been captured by residents’ security cameras.
While visibility is somewhat obscured, the video shows Mr. Koh’s car hemmed in and halted by the three SUVs. Men, some with their faces covered, get out of the vehicles and approach his car.
Two men on motorcycles order approaching vehicles to keep their distance. There is a crash as Mr. Koh apparently tries unsuccessfully to escape. Then all the vehicles drive off quickly together.
One witness reported the abduction to the police. A piece of Mr. Koh’s license plate was later found on the street. But the police have made no progress in solving the case.
The motive remains unclear, but Mr. Koh had been threatened several years earlier for preaching in settings where Muslims could be swayed. It is illegal in Malaysia to try to convert Muslims to Christianity.
Three other disappearances since late 2016 also involve victims who challenged the prevalent Malaysian view of Islam.
Pastor Joshua Hilmy, a convert to Christianity from Islam who was known to preach his new religion freely, disappeared around Nov. 30, 2016, along with his wife, Ruth Sitepu. They packed no belongings and their car is missing.
A week earlier, Amri Che Mat, who was said to promote a Shia interpretation of Islam in this predominantly Sunni nation, disappeared as he was driving near his home in Perlis, Malaysia’s northernmost state.
Just before midnight on Nov. 24, 2016, four-wheel-drive vehicles surrounded his car, a witness said. He car was later found abandoned. Mr. Amri, the founder of a charity group called Perlis Hope, has not been heard from since.
Earlier this month, a police officer came forward and told Mr. Amri’s wife, Norhayati Mohamed Ariffin, that a team of police officers had kidnapped her husband and Mr. Koh.
He identified the officers in charge and indicated that the abductions were motivated by the victims’ religious activities, Ms. Norhayati said. She provided the information to the police, including the name of the informant.
“I urge the police to investigate these serious allegations with urgency and to find my husband Amri Che Mat and also Pastor Raymond Koh and return them to their loved ones immediately,” she said.
Thomas Fann, the chairman of Engage, a Malaysian human rights group, said there have been at least nine other cases of forced disappearances, often targeting criminal gang suspects.
He expects more victims’ families to come forward and he urged the government to investigate the role of the police in these cases.
“The police are supposed to uphold law and order and human rights,” said Susanna Liew, Mr. Koh’s wife. “They are not supposed to engage in these clandestine operations.”
Human rights activists are also seeking an investigation into deaths of detainees in jails, prisons and immigration centers. Some advocates estimate that there were more than 1,000 wrongful deaths in custody during the Najib years.
Some were victims of police abuse and torture, they say. Many were victims of neglect. Most were illegal immigrants or suspected criminals.
Medical examiners have been known to cover up abuse in cases where evidence shows that the police were responsible, said Mr. Paulsen of Lawyers for Liberty.
During his first week in office, Mr. Mahathir called for an end to torture and for inquests to determine how detainees died.
“This is a good start,” said Sevan Doraisamy, executive director of Suara Rakyat Malaysia, a human rights group that focuses on justice issues. “This was never mentioned by the former prime minister.”
Cynthia Gabriel, executive director of the Center to Combat Corruption and Cronyism in Kuala Lumpur, called for new investigations into two high-profile killings connected to corruption cases involving Mr. Najib.
One is the 2006 murder of a Mongolian woman, Altantuya Shaariibuu, 28, who helped negotiate Malaysia’s purchase of two Scorpène-class submarines from France while Mr. Najib was defense minister. The French government is investigating whether Mr. Najib and his associates received more than $130 million in kickbacks.
Ms. Shaariibuu, who complained that she had not received a promised $500,000 share, was killed by two of Mr. Najib’s bodyguards, who then blew up her corpse using military explosives. The bodyguards were convicted, but no motive was ever established. Some suspect they blew up the body to hide something.
In a letter to Mr. Mahathir last week, the president of Mongolia, Khaltmaagiin Battulga, asked him to bring about justice in the case, which he said had harmed relations between the two countries.
Ms. Gabriel also urged the government to investigate the 2015 kidnapping and murder of Kevin Morais, a prosecutor who was investigating Mr. Najib over the money missing from the state investment fund.
The police say Mr. Morais was murdered because of his role in a different case, but his brother, Charles Morais, has long maintained that he was killed because he knew too much about Mr. Najib and the money.
“There are many murders unsolved and linked to one scandal or another,” Ms. Gabriel said. “There should be a thorough cleanup of the system. There is so much that has gone wrong over 60 years.”
Sharon Tan contributed reporting.