Force India on Wednesday confirmed it has instigated legal action in the UK against rival F1 team Lotus.
In a media statement, the Silverstone based team said the Malaysian-backed team's technical boss Mike Gascoyne and Italian wind tunnel Aerolab are also being sued.
It has been reported that Force India claims a wind tunnel model of its 2009 car left in the Aerolab facility was used as the basis for Lotus' current T127 racer.
Before working with Lotus, Briton Gascoyne also worked alongside Aerolab with Force India.
A Lotus spokesman on Tuesday said Aerolab "vigorously denies any wrongdoing and has provided Lotus Racing with a full indemnity in relation to the claim".
Force India said on Wednesday: "(The team) states these are very serious claims and therefore it would not be taking such action if it could not provide supportive evidence."
The team said a complaint has also been filed with Italian authorities.
It has been speculated that the dispute is actually about money, after Aerolab said late last year that it is pursuing Force India for "serious and persistent breaches of contract".
Force India added that "it is now for the competent courts to decide whether, indeed, this outstanding amount should be paid to Aerolab given the seriousness of these current allegations".
