Terming as "improper" the discharge of CPI(M) Kerala state Secretary Pinarayi Vijayan in the SNC Lavalin corruption case by a CBI court, BJP leader Subramanian Swamy today said the high court should quash it.

"This discharge is improper and the high court should strike it down," Swamy told reporters here.

"I have read the FIR (in Lavalin case). There was a strong prima facie case laid out. How would this man be discharged?" he asked.

Alleging that CBI, which has "worked" not under court monitoring but under the state government, had been forced to perform "like a parrot" as the apex court had stated.

"There seems to be some underlying 'deal' between the CPI(M) and Congress that CPI(M) will stop bothering the Chief Minister and then they will let Pinarayi Vijayan free. This looks like a match fixing," he alleged.

A CBI court in Thiruvananthapuram had on November 5 dropped Vijayan and five others from the list of accused in the case dating to mid 1990s when he was power minister in the LDF Ministry.