Antwerp Mystery: What Happened to Ken Heyrman?

Published: Updated: 0 comment

Ken Heyrman was born on July 26, 1985, to Rudi Heyrman and Tinny Mast in Antwerp, Belgium. Tinny (also spelled Tiny) had married for the first time when she was only 16. Ken’s sister, Kim Heyrman, was born a year later. Ken and Kim have different fathers. Tinny divorced Kim’s father a few months after Kim’s birth. Tinny then married Rudi Heyrman, and he adopted Kim. Rudi and Tinny eventually divorced, and Tinny married a third time to Manuel Lanssens. The couple had a son, Axel, in 1992. By January 1994, Tinny was pregnant with her fourth child.

On January 4, 1994, Kim, 11, and Ken, 8, took a tram from their home in Borgerhout, Antwerp, to watch a football (soccer) game by one of their friends in Merksam. The siblings planned to spend the night at that friend’s home following the game. The following day, Tinny, 28, worried when her children never returned home. She discovered they never reached the game or the friend’s house. A witness saw them for the last time at a tram stop near the Sportpaleis (Sports Palace), about halfway between Borgerhout and Merksam.

Tinny reported her children missing to the police. However, they did not take her seriously, assuming the children ran away and would eventually return. She miscarried on January 13, 1994, eleven days after the disappearance of Kim and Ken.

Tinny began searching for her children, assisted by family members and friends. The group scoured where the kids were last seen, including nearby Antwerp Dock but found no sign of the children.

Frustrated, Tinny notified reporters to spread the word about her missing children, which angered the authorities. Shortly after, they questioned her for hours, pointing the finger at her. Tinny believed they did this because she was low-income, uneducated, and had been with several men. In other words, they did not believe her because they saw her as a low member of society. 

But their suspicion of Tinny changed five weeks after the children disappeared.

On February 11, 1994, Kim’s body was found in Asiadok, a short distance from the Sportpaleis. She had been sexually assaulted and killed violently. 

Two weeks later, someone dropped off Ken’s jacket, where his sister’s body was found, and his football gloves in Tinny’s letterbox a few weeks later. Ken has never been located. 

According to a Belgium Reddit user, the children’s stepfather wrote a letter to the prosecutor’s office claiming he killed them, then threw their bodies into the Albert Channel about a half mile from where Kim was found. Lanssens then attempted suicide and was sent to a mental hospital. I could not verify this information or anything additional on Lanssens. And the user gave no possible motive for Lanssens to kill the children. One might speculate it was a retaliation killing against Tinny.

Another possible suspect is Belgium serial killer Marc Dutroux, who tortured, raped, and murdered six girls, including eight-year-old classmates Julie Lejeune and Mélissa Russo, between 1995 and 1996. The murder of Julie and Mélissa sparked outrage in Belgium when the public learned the girls died from starvation in Dutroux’s dungeon four months after his arrest. He claimed his wife was supposed to feed and care for them, but family members did not believe the girls were there then. 

Dutroux was the alleged leader of an international child trafficking ring between the mid-1980s and late 1990s. It is a network that many suspect the Belgium police of covering up to this day.

One of the girls testifying during Dutroux’s trial was Witness XI, later revealed to be Regina Louf, born in 1968, who told police about the murder of 15-year-old Katrien de Cuyper. Louf claimed a pedophile group forced her to kill Katrien after they had sexually abused the teenager. Louf said Dutroux and other group members also abused her numerous times.

Katrien vanished on December 17, 1991, in Antwerp. She visited her boyfriend in Lange Lobroekstraat and telephoned her parents at 9:30 p.m., telling them she would take the bus home. Afterward, Katrien walked to the bus stop alone because it was raining, and she saw no reason for her boyfriend to accompany her.

However, Katrien missed the bus and was last seen at 10:45 p.m. at Les Routiers café, near her boyfriend’s home and the Sportpaleis. Katrien made another call from the cafe, but the police could not trace the call. Les Routiers, now closed, is a short distance from Asiadok, where Kim’s body was found.

The second floor of the building that housed the cafe was once used as a studio for adult films. 

On June 19, 1992, six months after Katrien vanished, her naked body was found during groundwork in the Port of Antwerp, also near both the cafe and Asiadok. She had been strangled, and her body severely decomposed after being submerged in hydrochloric acid.

Investigators claimed they found no evidence tying Dutroux to Kim’s murder, Ken’s disappearance, or Katrien’s murder. Detectives arrested another suspect in 2006 for Katrien’s murder but let him go for lack of evidence.

In 2014, Tinny had Ken declared dead.

“I only now feel ready. I think Ken deserves a real goodbye,” she said. “That is an extremely difficult step. I want to be able to turn that page, but it book will never come. People say time heals all wounds. Forget it, that’s bullsh*t.”

Ken Heyrman and Kim Heyrman
Ken Heyrman and Kim Heyrman


Bussell, Carter. “The Unsolved Murder of Katrien De Cuyper.” Conspiracy Dossiers. July 4, 2020.

“Ken Heyrman.” The Doe Network.

“Mother has missing son declared dead in court.” VRT News. March 10, 2014.

Roos, Robin. “Murdered Children And Pedophile Networks In The Low Countries.” Cult Nation. January 15, 2021.

“Tiny Mast commemorates the 20-year disappearance of her children Kim and Ken.” GVA. January 4, 2014.

About Me

True Crime Diva

True Crime Diva

I've blogged true crime since 2010, happily taking up only a tiny corner of the internet. I'm not here for attention; I'm here to tell you their stories.

You cannot copy the content of this page!

Skip to content