Toy company Mattel has become the recipient of some barbed criticism from bitter rivals MGA Entertainment after the latter accused them of spying.

MGA allege that over a 15 year period Mattel workers, with the approval of executives, were infiltrating private showrooms and stealing product ideas and advertising strategies from companies including Hasbro, Lego and Sony.

Court papers lodged with Los Angeles federal court cite Mattel’s chief executive, Bob Eckert, as being the recipient of reports generated from these illicit forays.

It is the latest twist in a bitter tussle between the two rivals, who manufacture Barbie dolls and Bratz dolls respectively and follows claims from Mattel that the initial Bratz doll designs were made by an employee of theirs while still under contract.

A judge ruled in July however that it was unfair to hand Mattel the Bratz line, decreeing their value to be “overwhelmingly” created by MGA.

In a statement Mattel said they were looking forward to defeating MGA in court.