HONG KONG (Reuters) - Speculation that Guangzhou Evergrande and Beijing Guoan are to go head-to-head for the signature of striker Pierre-Emerick Aubameyang has prompted the Chinese Football Association (CFA) to warn both clubs they risk incurring hefty levies if they break Chinese Super League transfer regulations.

Chinese media reported that the clubs are in talks with Borussia Dortmund for the signature of the Gabon international who has long been linked with a move away from Germany having regularly topped the Bundesliga scoring charts.

A fee in the region of 70 million euros (61.73 million pounds) has been touted as the figure needed to bring the forward to China.

But with regulations put in place last year imposing a 100 percent tax on transfer fees over $70 million for foreign players, the CFA has stepped in to remind both clubs the rule remains in place.

“Recent reports claiming two Chinese Super League clubs will compete on price for a foreign player have attracted a lot of attention,” a statement said.

“The Chinese Football Association has paid close attention to this matter and has sent a letter to the respective clubs to ask for an explanation. The CFA will deal seriously with any violation of its regulations.”

The levy was put in place last year to curb spending on foreign players after Shanghai SIPG broke the Asian transfer record with the 60 million-euro capture of Oscar from Chelsea in January.

The move appeared to work, with Anthony Modeste’s two-year loan to Tianjin Quanjian from FC Koln in Germany the only signing of note during the close season window.

However, the CFA warned it would continue to watch the situation closely to ensure against any breaches.

“We will monitor the transfer market ahead of the new season. The CFA will not permit any violation and will not go easy on those who break the rules,” it said.