Calcutta: Former national racing champion Ashwin Sundar and his wife Niveditha died in a car accident at MRC Nagar in Chennai on Saturday.

The 31-year-old Sundar and Niveditha were trapped inside their luxury car when it caught fire after hitting a roadside tree. They were charred to death inside the vehicle, the police said. The accident took place around 3.30 am.

Police officials claimed over-speeding was the reason behind the crash.

Fire and rescue services personnel from Mylapore also rushed to the spot but it took around half-an-hour to put out the flames.

Sundar had won the national title in four and two-wheeler events on several occasions. His wife Niveditha was a doctor.

In 2006, he was adjudged Champion of Champions in India after winning the 115cc 4-stroke and 150cc 4-stroke titles. He had signed a deal with German racing team Ma-Con Motorsport and drove in the German Formula Volkswagen ADAC Championship in 2008.

In 2012 and 2013 he was India's F4 champion.

The Federation of Motor Sports Clubs of India (FMSCI) president and former race driver Akbar Ebrahim tweeted: "It's a sad day for motor sports. I knew Ashwin since he was an infant and I saw him excel in all formats of the sport. May his and his wife's souls rest in peace."

Former Indian F1 driver Karun Chandhok too expressed shock. "Very sad to hear this morning that the young Indian National racing champion Ashwin Sundar and his wife were killed in a road accident.#RIP."

Police said Sundar and his wife were trapped inside the car as it got jammed between the tree and a wall.

People who spotted the vehicle on fire, alerted the Chennai city police control room, and a team of police personnel from the Adyar traffic investigation wing rushed to the spot.

Adyar traffic investigation wing inspector of police Vanitha and her team broke open the car and recovered the charred bodies.

Initially, they could not be identified. Later, when the vehicle registration number was checked, the racer could be identified. The couple, who lived in Alapakkam near Porur, were visiting a friend at MRC Nagar in Raja Annamalaipuram. The accident happened when they were returning home.

Ashwin had been a familiar figure in the pit-lanes for more than a decade, shooting to fame in the karting circuit at the turn of the millennium.

Ashwin also enjoyed success in two-wheeler racing, winning national titles in the 115cc 4-stroke class and the 150cc 4-stroke class in 2006 and notching podiums in the 2007 FIM Asia Road Racing Championship. He had last raced in the 2016 JK Tyre LGB F4 series.

His fellow racers and officials remember Ashwin as polite and soft-spoken off the track and an aggressive racer on it.

"He was always so polite and respectful," said FMSCI vice-president J. Prithviraj.

Fellow Chennai racer Aditya Patel, who achieved much success in the Audi R8 LMS Cup this year, has known Ashwin since they were kids. "We go back a long way, right from when we started karting together," Aditya said.