San Francisco-based startup Telesocial has reportedly filed a lawsuit against French telecoms group Orange, over a social calling application that enables users to make calls via social networks.

In its filing with the California court, Telesocial alleged that the French firm ‘unlawfully obtained information to reverse engineer a knock-off product that Orange and Facebook would later go on to claim they developed from scratch."

Telesocial claims that its app, dubbed PartyCall, was based on its proprietary code that it shared with the telecoms firm during negotiation of an agreement, which was later dismissed by the telecoms carrier.

In its complaint, which was cited by the FT, Telesocial noted: "The twisted path that led to Stéphane Richard and Sheryl Sandberg being on stage together that day was paved with concerted deceit, misappropriation, old-fashioned theft, and, above all, remarkable hubris."

"Banding together, these tech industry giants decided to steal Telesocial’s social calling technology, and arrogantly cast Telesocial aside believing they had duped the small start-up company into disclosing the information they needed to copy Telesocial’s products."

Rolled out by Orange chief executive Stéphane Richard in November 2012, the PartyCall app allows people to chat through Facebook profiles.

Suggesting the latest legal action as derived from the similar rows in several Paris courts during the last year or more, Orange said:

"In the last six months, two separate courts in France, including the Paris Court of Appeal, have found against TeleSocial with regards to these complaints,"

"This reinforces our view that TeleSocial’s complaints are totally lacking in merit."