Robin van Roosmalen first made himself heard on Friday after the former kickboxing world champion was seriously injured in a traffic accident on Wednesday.

His 29-year-old sister Melissa was killed in the accident.

"Thanks for all the messages, love and support, we really appreciate that. The operation went well", 31-year-old Van Roosmalen writes on Instagram.

"I can't respond to all messages, but I know I've read them all."

The accident took place on the A2 near Nieuwegein on Wednesday afternoon.

Van Roosmalen and his sister were standing still on the hard shoulder when they were hit by a truck.

The accident was so serious that the motorway in the direction of Utrecht had to be closed for several hours and long traffic jams were created.

The police arrested the driver of the truck.

Robin van Roosmalen in action as GLORY kickboxer in 2018.

Robin van Roosmalen in action as GLORY kickboxer in 2018.

Photo: ANP

Van Roosmalen had to fight for his life

Melissa van Roosmalen died of her injuries on the spot.

GLORY, of which Robin van Roosmalen was former world champion in the light and featherweight, reported that the fighter was in a critical condition.

It is not known exactly what injuries Van Roosmalen suffered.

There is talk of various bone fractures.

GLORY reported on Thursday at a press conference for the upcoming fight between Rico Verhoeven and Jamal Ben Saddik that Van Roosmalen was still fighting for his life.

Verhoeven and Ben Saddik expressed their support to their colleague.

Van Roosmalen lost his championship belt in a lost fight in 2018 in the Johan Cruijff ArenA.

Then he looked for a new challenge in MMA.

He settled in the United States and signed a contract with MMA bond Bellator.

Due to the corona crisis, he could not yet make his debut in that organization.