Seven lawsuits have been launched in Russia and "hundreds" dozens more are in the pipeline against US tech giant Apple which has already admitted to slowing the performance of older iPhone models, a lawyer for some of the plaintiffs said Wednesday.

"We have sent seven lawsuits to Moscow courts—two have been received by the Tverskoy (Moscow district) court and in all we are going to send ten by the end of the week," Maxime Karpov, representing legal services firm NLF Group, told AFP.

Interfax news agency had earlier quoted the court as saying it had received two of the lawsuits by Tuesday evening demanding compensatioo of 800,000 rubles (around $11,500) from Apple's Russian subsidiary.

NLF Group and the Lex Borealis lawyers firm which is also representing the claimants, said in a joint statement they were handling "at least several hundred" claims running into "several tens of millions of rubles".

Karpov told AFP: "If hundreds of complaints have come our way in a few days then I am sure there will be thousands across Russia. We are concentrating on Moscow and region to keep our costs down but there is nothing stopping us ... undertaking similar moves in the provinces."

Apple, facing a US class action and a legal enquiry in France into "planned obsolescence" of its smartphones, with a new model released annually, admitted last month it was deliberately slowing down performance of older models to bolster "durability."

The company apologised and promised to discount replacement batteries for some handsets following uproar from some iPhone users after news of battery problems stoked concerns the company was unfairly nudging consumers to upgrade.