The war of words between Red Bull's Sebastian Vettel and HRT's Narain Karthikeyan took a turn for the worse with the Indian F1 driver taking an aggressive stance and calling the double world champion a "cry baby".  

The controversy goes back to last Sunday's rain-disrupted Malaysian Grand Prix which saw Vettel finish 11th following a collision with Karthikeyan's HRT car. Vettel was running fourth when he collided with Karthikeyan, collecting a right-rear puncture that dropped him out of the top 10.

The German driver had blamed Karthikeyan for failing to pick up a point and called the Indian an "idiot" and "cucumber".

Sebastian Vettel 
Sebastian Vettel.

Talking to German television, he had said, "Just like on the normal roads you have some idiots driving around. It seems like there is also one driving here." He added, "As in real life, there are a few cucumbers on the road."

Replays of the incident appear to show Karthikeyan gave Vettel enough room to pass. Vettel was also seen showing his middle finger to Karthikeyan during the race.

Karthikeyan -- who tangled with McLaren's Jenson Button at Turn 9 shortly after the race restart -- expressed regret over his collisions with the Brit and with Vettel. Button later took responsibility for his incident.

Karthikeyan told AUTOSPORT: "I was turning in, there was a bang and I am sorry for Jenson. "Then there was the incident with VetteI. I had to come back on the track from the kerb, and he was there unfortunately and I could not do anything." Karthikeyan said he spoke to both men to say sorry after the race, AUTOSPORT reported.

Narain Karthikeyan.

But the Karthikeyan seems to have changed his stance now.

In an interview with Hindustan Times, India's first Formula 1 driver said that it was a shameful response from a world champion who is not known for being particularly outspoken. "It is really unprofessional," the Hindustan Times quoted him as saying.

"For a driver who has achieved so much, to take out his frustrations on me just because he is having a difficult year is really sad. One does not expect a professional sportsman to be such a cry baby."